Ch. 6 energy and oscillations, Exam 2

Only forces parallel to the motion do work.

(horizontal work)

Compared with a force, a torque involves

-leverage -rotation -distance from an axis of rotation

The PE of a spring is 0.3 when it is compressed 0.04 to the left of its equilibrium position. At this point it comes to its leftmost position. What is its KE when it RETURNS to the equilibrium point?

0.25 Joule and moving to the right

If the speed of sound is 340 meters per second and a tuning fork oscillates at 440 cycles per second, what is the wavelength λ of the sound produced?

0.773 meter

Suppose that water waves coming into a dock have a velocity of 1.2 m/s and a wavelengths of 1.4 m. With what frequency do these waves meet the dock? Round the final answer to two decimal places.

0.86 Hz

The density of aluminum is 2700 kg/m3. An aluminum block has a mass of 0.25 kg. The buoyant force exerted on this block when it is completely submerged in water of density 1000 kg/m3 is approximately:

0.91 N

On a balanced seesaw, a boy three times as heavy as his partner sits

1/3 the distance from the fulcrum

The circumference of a bicycle wheel is 2 meters. If it rotates at 1 revolution per second then its linear speed is

2 m/s

A bullet of mass 0.010 kg and speed of 200 m/s is brought to rest in a wooden block after penetrating a distance of 0.10 m. This process takes 0.02 second. The magnitude of the impulse delivered to the bullet by the block during this time is

2.0 N·s.

if the speed of sound is 1100ft/s and tuning fork oscillates at 440 cycles/s; what is wavelength of the sound produced?

2.5ft (lambda=v/f)

fishing boat captain returns to port saying "waves are 4m high" he probably means that the amplitude of the waves is:

2m (amplitude is distance from original position above or below)

Consider standing waves on a string shown below. The snapshots of the string is shown at two points in the cycle, in order to show the shape of the standing wave better.

3

Consider standing waves on a string shown below. The snapshots of the string is shown at two points in the cycle, in order to show the shape of the standing wave better. Which of the waves shown have the longest wavelength?

3

If the speed of a car is tripled, the impulse required to stop the car changes by a factor of

3.

Sound travels through air at a high but finite speed. Select the choice below which gives a numerical value of speed closest to the speed of sound in air.

300 m/s

to produce an A note (440hz) at 20 degrees C, a saxophone must create how long an effective air column?

39 cm

speed of electromagnetic waves in air is 3x10^8m/s; what is wavelength of FM radio waves frequency 1x10^8hz?

3m (v=f*lambda)

If the speed of a car is DOUBLED but the brakes apply the same force, the distance required to stop the car changes by a factor of

4

If the speed of a car is doubled but the brakes apply the same force, the distance required to stop the car changes by a factor of?

4

A string is held taut between two supports 2.0 m apart. The longest and next-longest possible wavelengths for standing waves are

4 m and 2 m.

A 3 kg block, initially moving due east at 6 m/s, is acted upon by an impulse having magnitude 6 N·s and direction due west. The final velocity of the block is

4 m/s east.

An object with a kinetic energy of 40 J is stopped in a distance of 0.01 m. The average force that stops the object is

4,000 N.

If the speed of a car is doubled but the brakes apply the same force, the distance required to stop the car changes by a factor of

4.

Suppose that the rifle weighs 100 times as much as the standard caliber bullet for the rifle. If the muzzle velocity of the bullet is 500 m/s, what is the recoil velocity of the rifle, if it weren't supported as the bullet was being fired?

5 m/s

on a day when the speed of sound in air is 340m/s, lightning bolt is observed and resultant thunder is heard 2s after; about how far away was the lightning?

680m (d=vt--it takes about 5s to travel a mile or 1609m)

waves passing anchored ship are 20ft from crest to crest and each minute, 4 crests pass; speed of wave is:

80 ft/min (v=f*lambda = 4*20)

The glass in a window is 30 inches wide and 20 inches tall, and standard atmospheric pressure is 14.7 pounds per square inch. What net force would result on the glass if the air pressure outside the house were 1% lower than the air pressure inside?

88 pounds outward.

string is held taut between two supports 4m apart; the two longest possible wavelengths for standing waves are:

8m and 4m (if both ends are fixed, the string can contain half a wavelength so fundamental=8m; second harmonic allows complete wavelength to be contained in tube; lambda=2L/n for n=1, lambda=8m, for n=2, lambda=4m)

The density of aluminum is 2700 kg/m3. An aluminum block has a mass of 2.5 kg. The buoyant force exerted on this block when it is completely submerged in water of density 1000 kg/m3 is approximately

9.1 N.

A small radio-controlled cars motor rated at 6 watts output is capable of performing _____ Joules of work in 15 seconds

90 Joules

Suppose we replace the mass in the video with one that is four times heavier. How far from the free end must we place the pivot to keep the meter stick in balance?

90 cm (10 cm from the weight)

When you life a heavy 5.0kg crate straight up from ground level to a height of 2.0m above ground level, then you have changed the crates gravitational PE by,

98 Joule (PE=m*g*h)

A 3 kg block, initially moving due east at 6 m/s, is acted upon by an impulse having magnitude 6 N·s and direction due west. The final velocity of the block is

A 3 kg block, initially moving due east at 6 m/s, is acted upon by an impulse having magnitude 6 N·s and direction due west. The final velocity of the block is

A box is pushed across a rough horizontal floor by a force acting parallel to the floor in the direction of motion. A force doing no work during the motion is

A box is pushed across a rough horizontal floor by a force acting parallel to the floor in the direction of motion. A force doing no work during the motion is

Which of the following statements is true?

A floating ocean liner will displace its own weight of water.

In order for a body to exhibit simple harmonic motion there must be

A force drawing the body toward the center and increasing with distance away from the center

In order for a body to exhibit simple harmonic motion there must be?

A force drawing the body toward the center and increasing with distance away from the center.

Choose the statement below which correctly defines or describes torque.

A given amount force can produce only a fixed amount of torque.

Choose the correct statement below regarding amplitude, frequency, and period of a simple harmonic oscillator motion.

A given simple harmonic oscillator oscillates at a fixed frequency, regardless of the amplitude of its motion.

Choose the statement below which correctly distinguishes between a transverse wave and a longitudinal wave.

A transverse wave oscillates in direction perpendicular to the direction of wave propagation, while a longitudinal wave oscillates in the direction along the direction of wave propagation.

What is the relationship between the center of gravity and the support base for an object that is in stable equilibrium?

A vertical line through the center of gravity must pass inside the support base of the object

Why can't you stand with your heels and back to a wall and then bend over to touch your toes and return to your stand-up position?

A vertical line through the center of gravity of your body is in front of the tips of your toes, which is outside your support base

Why doesn't the Leaning Tower of Pisa topple over?

A vertical line through the center of gravity passes inside its support base

One morning you discover that a tire on your auto is in need of air. As you add air to the tire, which of the following statements is true?

A. The pressure of the air in the tire increases. B. The number of moles of air in the tire increases. C. The density of the air in the tire is increased D. All of the above

When a baseball hits the bat, the impulse delivered to the ball is increased by A.) "Follow through" on the swing B.) Rapidly stopping the bat after impact C.) Impulse can not be changed D.) Letting the bat coil upon impact

A.) "Follow through" on the swing Impact will be increased by increasing the time of contact

A bullet of mass 0.010kg and speed of 100m/s is brought to rest in a wooden block after penerating a distance of 0.10m. The work done on the bullet by the block is A.) -50J B.) Zero C.) 50J D.) 0.001J E.) -0.001J

A.) -50J KEF-KEI=Work W = -1/2 * 0.01 * 100^2 W= -50J

A 20kg child runs at 4.0m/s and jumps onto a shopping cart , which also has mass 20kg. Assuming the child rides on the cart after the collision, the speed of the child and the shopping cart, just after the child jumps on it is A.) 2.0m/s B.) zero C.) 3.0m/s D.)4.0m/s

A.) 2.0m/s Ptotal intial = Ptotal final 20 * 4 + 20 * 0 = (20+20) vfinal 80 = 40 vf vf = 2.0 m/s

If the speed of a car is doubled, the work to stop the car changes by a factor of A.) 4 B.) 1 C.) 2 D.) 1/2 E.) 1/4

A.) 4

In order for a body to exhibit simple harmonic motion there must be A.) A force drawing the body toward the center and increasing with the distance away from the center B.) A force drawing with the body toward the center and decreasing with the distance away from the center C.) A constant force pushing the body away from the center D.) A constant force drawing the body towards the center E.) A force pushing the body away from the center and increasing with the distance away from the center

A.) A force drawing the body toward the center and increasing with the distance away from the center

A box is pushed across a rough horizontal floor by a force acting parallel to the floor in the direction of motion. A force doing negative work on the body is A.) Friction B). A fictitious force C.) The applied force D.) Gravity E.) Normal reaction to the force of the floor upward on the body

A.) Friction Rough surface = Friction Friction Force is against the motion

The purpose of an air bag in an auto is to A.) Increase your body's stopping time during a collision B.) Reduce your speed just before a collision C.) Reduce the need for good brakes on your car D.)Increase the force applied to you during a collision

A.) Increase your body's stopping time during a collision Impulse = Force * Time As the time increases => Force decreases

A brick slides across a horizontal rough surface and eventually comes to a stop. What happened to the kinetic energy of the brick? A.) It was converted to other forms of energy, mostly heat B). It was converted to a potential energy of friction C.) It was simply destroyed in the process of stopping D.) Nothing, it is still in the brick but now it is called potential energy

A.) It was converted to other forms of energy, mostly heat Due to friction between brick and rough surface

A body is suspended from a spring hanging vertically. The bodt is then pulled downward so the spring stretches. Consider the change in the elastic potential energy (EPE) of the spring and the change in gravitational potential energy (GPE) as the body is pulled down A.) The GPE decreases while the EPE increases B.) Both the GPE and the EPE decrease C.) The EPE increases but the GPE is unchanged D.) The GPE increases along with the EPE E.) The GPE decreases but with the EPE is unchanged

A.) The GPE decreases while the EPE increases

A REFRIGERATOR WEIGHING 1500N IS TO BE LIFTED ONTO A TRUCK BED THAT IS 1.0m ABOVE THE GROUND. WHEN PUSHED UP A SLANTING RAMP 2.0m IN LENGTH A FORCE OF ONLY 750N IS REQUIRED TO MOVE IT AT CONSTANT VELOCITY. COMPARING THE WORK INVOLVED IN LIFTING THE FRIDGE STRAIGHT UP TO THE WORK IN PUSHING IT ALONG THE RAMP, THERE IS

AN EQUAL AMOUNT OF WORK IS REQUIRED IN EACH CASE

Bottom of hill with sled: No height No PE Max KE

At the bottom of hill when sledding.

A car moving east collides with a truck moving north. The vehicles have the same speed but the truck has twice the mass of the car. If the vehicles stick together after the collision, what is the path followed by the vehicles after the collision?

B

For a 0.1kg frog to jump to a height of 1.0 meter require an energy of about A.) 10J B). 1.0J C.) 0.5J D.) 0.1J

B). 1.0J The energy = Potential Energy E = PE = MGH = 0.1 * 9.8 * 1 = 0.98 = 1.0J

A child riding on a swing rises to a height of 1.0m above the lowest point. Another child of equal mass whose speed at the lowest point is twice as great will rise A.) To a height which depends on the mass B). Four times as high C.) Twice as high D.) To the same height

B). Four times as high

Which of the following is possessed by a moving object but not a stationary A). Mass B). Kinetic Energy C.) Inertia D.) Energy

B). Kinetic Energy K.E = 1/2mV^2 So object must be moving!

Work is not being done on an object unless A). Object is being accelerated B). Object is moving C.) Speed is constant D.) Net force on the object is zero

B). Object is moving Work = Force * Displacement

Virgil rides a skateboard (combined mass 100kg) at 4m/s and Jill rides a bicycle (combined mass 64kg) at 5/ms A.) Jill has the greater kinetic energy B). Virgil and Jill have equal kinetic energies C.) Virgil has the greater kinetic energy

B). Virgil and Jill have equal kinetic energies KE = 1/2mv^2 Virgil: 1/2 * 100 * 4^2 = 800J Jill: 1/2 * 64 *5^2 = 800J

A hot air balloon derives its lift from the property of fluids as stated by

Archimedes' Principle.

Work is done on an object to increase its total energy. Which one of the following is true?

Both the kinetic energy and potential energy can be larger.

It is observed that as bubbles rise in a deep column of water, the diameter of the bubbles increases. This is best explained by

Boyle's Law

Conservative forces are forces for which the energy can be completely recovered

E = KE = 1/ mv2 Friction is not conservative

The potential energy of a spring of constant K that has been stretched to a distance x is given by A.) (1/2)k/x B). (1/2)kx C.) kx D.) kx^2 E.) (1/2)kx^2

E.) (1/2)kx^2 PE= (1/2)kx^2

A box is moved 10M across the floor by a force of 20N acting along the direction of motion. The work done by the force is A.) 100J B.) 20J C.) 2.0J D.) 30J E.) 200J

E.) 200J Work = Force * Distance = 20 * 10 = 200J

A painter of mass 80kg climbs 3.0m up a ladder. The painter's potential energy has increased by A.) 1284J B). 261J C). 240J D.) 784J E.) 2352J

E.) 2352J PE = MGH = 80 * 9.8 * 3 = 2358J

Force F, acting for time T and over a distance of D, gives impulse I. To get the same impulse using half the force it would be necessary for the force to act A.) Over a distance 2D B.) Over a distance 4D C.) For half the time T D.) Over half the distance D E.) For a time 2T

E.) For a time 2T

The conversion of the initial PE of a person on a sled on a smooth icy slope into KE at the bottom is an example of the principle of conservation of __________

Energy

Conservation of energy means the total energy (kinetic plus potential energies) of a system remain constant

Energy is conserved if there are no non-conservative forces doing work on the system

A lever is used to life a rock. Will the work done by the person on the lever be greater than, less than, or equal to the work done by the lever on the rock?

Equal to. (the work done by the person can never be less that the work done by the lever on the rock. If there are no dissipative forces will be equal

Negative work is the work done by a force acting in a direction OPPOSITE to the objects motion

Example: car skidding to stop

A simple machine multiplies the effect of an applied force

Example: lever, pulley

The mechanical advantage of a simple machine is the ratio of the output force to the input force

Example: pulley

What is required to change the angular momentum of a system?

External torque

When a wave crosses from one medium into another in which the wave speed is lower, the frequency is unchanged. The wavelength

Decreases

Choose the statement below which correctly defines or describes density.

Density is a property of the substance and remains constant when more or less of the same substance is present.

Choose the statement below which correctly distinguishes between nodes and antinodes.

Destructive interference occurs at the locations of the nodes, while constructive interference occurs at the locations of the antinodes.

Door B is twice as wide as door A, but both doors have the same height and the same mass. A person pushes on the edge of the two doors with the same force. Which door opens more quickly?

Door A Even though the torque applied on door A is half that of door B, the moment of inertia of door B is four times higher than that of door A (the moment of inertia is proportional to the square of the width of the door)

Shown in the figure is a view of a door from above. Three forces are shown acting on the door. Which force is causing the largest torque on the door?

Force A The torque of force A is 150 N⋅ m(τ=Fr=(300 N)(0.5m)=150 N)

Which of the following most correctly describes the relationship between force and momentum?

Force is the rate of change of momentum.

A box is pushed across a rough horizontal floor by a force acting parallel to the floor in the direction of motion. A force NO WORK during the motion is

Gravity

A box is pushed across a rough horizontal floor by a force acting parallel to the floor in the direction of motion. A force doing no work during the motion is?

Gravity

If a skater who is spinning pulls her arms in so as to reduce her rotational inertia by half, by how much will her angular momentum change? By how much will her rate of spin change?

Her angular momentum does not change. Her spin rate doubles

A figure skater is spinning with her arms extended. She now pulls her arms close to her body. What happens?

Her rotational inertia decreases.

A truck mass of 4000kg is at rest but free to roll with no resistance. If you push it forward with a force of 500N, the momentum at the end of 5s of pushing will be

Impulse = Change In momentum F * T = Pf - Pi 500 * 5 = Pf - 0 500 * 5 = Pf Pf = 2500

Choose the statement below which correctly describe relationship between impulse and other physical quantities.

Impulse gives the change of momentum.

A brick slides across a horizontal rough surface and eventually comes to a stop. What happend to the kinetic energy of the brick

It was converted to other energy forms, mostly heat

A brick slides across a horizontal rough surface and eventually comes to a stop. What happened to the kinetic energy of the brick?

It was converted to other energy forms, mostly heat.

If you toss a stick into the air, it appears to wobble all over the place. Specifically, about what place does it wobble?

It will rotate about the center of mass

An iceberg is floating in the ocean with 10% of its volume extending above the ocean's surface. What can you say about the iceberg?

Its density is close to but smaller than the density of water.

Joe lives on the equator, and Sally lives in Alaska. Which person has the higher speed due to Earth's rotation?

Joe Both Joe and Sally have the same rotational velocity. Joe is going faster than Sally because the equator is further from the axis of rotation than Alaska

Joe lives on the equator, and Sally lives in Alaska. Which person has the higher angular velocity due to Earth's rotation?

Joe and Sally have the same angular velocity Even though Joe is moving more quickly than Sally, they both have the same angular velocity because they both complete one revolution every 24 hours

Kinetic Energy is the energy associated with an objects motion

KE = 1/2 mv2

Which of the following in not a unit of power?

KiloWatt-hour

Which of the following is not a unit of power?

KiloWatt-hour

Other things being equal, the pole-vaulter having the greatest _______ energy prior to going into the jump should jump the highest

Kinetic

Which of the following is possessed by a moving object, but not by a stationary object?

Kinetic energy

Which of the following is possessed by a moving object?

Kinetic energy

Choose the statement below which correctly compares/contrasts momentum with kinetic energy.

Kinetic energy is a scalar, and momentum is a vector.

Consider an automobile on a surface road which is traveling at 30 mph. When it gets on a freeway and speeds up to 60 mph, how much did the automobile's kinetic energy increase?

Kinetic energy quadrupled.

Choose the statement below which correctly defines or describes "pressure".

Large force applied over a small area produces a large pressure.

A sample machine allows you to move ______ masses even though you apply _______

Larger, smaller force over a longer distance

Choose the statement below which INCORRECTLY describes a difference between liquids and gases.

Liquids are able to flow, but gases do not flow.

As the polar icecaps melt, the resulting water spreads over the entire Earth. This new mass distribution tends to make the length of a day

Longer

JJIM EXERTS A FORCE OF 500N AGAINST A 100kg DESK THAT DOES NOT MOVE. VIRGIL EXERTS A FORCE OF 400N AGAINST A 60kg DESK THAT MOVES 2m IN THE DIRECTION OF THE PUSH. MIK EXERTS A FORCE OF 200N AGAINST A 50kg DESK THAT MOVES 5m IN THE DIRECTION OF THE PUSH. THE MOST WORK IS DONE BY

MIK

To change the fundamental frequency of a guitar string, you can

Make it shorter, by pressing a finger of your left hand on the string

A mass hangs from a spring that is fixed to the ceiling. The mass is now pulled down and released so the mass oscillates up and down. Which of the following statements is true?

Making mass on the spring lighter will make it oscillate faster.

Choose the statement below which correctly defines or describes momentum.

Momentum is the quantity of motion, mass times velocity.

Which general pattern holds for various excited states in standing waves on a rope or string fixed at both ends?

More antinodes means shorter wavelengths.

When a force acts in a direction opposite to the motion _______ work is said to be done on the object

Negative

Virgil rides a skateboard (combined mass 100kg) at 4m/s, and jill rides a bicycle (combined mass 64kg) at 5m/s.

Virgil and Jill have equal kinetic energies

Some people say that based on the arrangement of its molecules, glass should be considered a liquid. If we think of glass as a liquid, in which of these properties is it most unlike other common liquids?

Viscosity

Work= mass*acceleration*distance

W=m*a*d (answer will be in Joules)

Which of the following in not an energy unit

Watt

Which of the following is not an energy unity?

Watt

Choose all statements below which correctly defines or describes "wave velocity" or "wave speed".

Wave velocity is the speed at which a disturbance travels through a medium.

Choose the statement below which correctly describes the relationship between wave speed, wave frequency, and wavelength.

Wavelength is given by wave velocity divided by wave frequency.

Choose the statement below which correctly defines or describes "wavelength".

Wavelength is the length of the smallest portion of the wave that repeats.

Each statement below compares the wavelength to another wave/oscillation characteristic. Choose the most appropriate comparison below.

Wavelength of a wave is like the period of an oscillator.

In a double-axel jump, a figure skater pulls in her arms as she pushes off the ice and completes a 2.5 turn in air before landing. (The figure below shows a diagram of a single-axel jump; double-axel jump includes an additional full turn in air).

When the figure skater pulls in her arms, she reduces her rotational inertia, which increases her rotational speed so that her angular momentum is conserved, and this allows her to complete more turns in air.

In a double-axel jump, a figure skater pulls in her arms as she pushes off the ice and completes a 2.5 turn in air before landing. (The figure below shows a diagram of a single-axel jump; double-axel jump includes an additional full turn in air). In order to perform this jump, most skaters start out with their arms stretched out, which they pull in shortly after the take-off. Which statement below most correctly explains the physics of this manuever?

When the figure skater pulls in her arms, she reduces her rotational inertia, which increases her rotational speed so that her angular momentum is conserved, and this allows her to complete more turns in air.

A child is drinking a liquid with a straw. Which of the following statements is true?

When the pressure in the straw is reduced, atmospheric pressure on the surface of the liquid pushes the liquid up the straw.

Work is equal to the force applied times the distance moved

Work= Force x distance (W=F*d)

Work is done on a large crate to tilt the crate so that it is balanced on one edge, rather than sitting squarely on the floor as it was at first. Has the PE of the crate increased?

YES.

If there is a frictional force opposing the motion of the block, does this frictional force do work on the block?

Yes, the frictional force does work

An isolated object is initially spinning at a constant speed. Then, although no external forces act upon it, its rotational speed increases. This must be due to

a decrease in the moment of inertia.

In which situation below is some work done? There is one correct answer.

a weightlifter raises weights from the ground to overhead position

Multiple the equation for linear momentum by radial distance r and you have

angular momentum

When an ice skater twirling on the point of a skate draws her arms in she ends up whirling faster. This is because

angular momentum is conserved.

A torque acting on a body tends to produce

angular rotation.

Using a longer-handled wrench to loosen a tight nut allows you to

apply more torque to the nut.

The angular momentum of an object can be changed only by

applying a torque.

The center of gravity of a basketball is located _______.

at its geometrical center

A vertically-held sledge hammer is easier to balance when the heavier end is

at the top, away from your hand

In which situation below is some work done? There is one correct answer.

backpackers hike up a gentle hill carrying 40-lb backpacks

Centripetal force does no work on a circularly-moving object because

centripetal force has no component in the direction of motion

The center of mass of a human body is located at a point that

changes as a person bends over

The purpose of an air bag in an auto is to

decrease the force applied to you during a collision.

repeatedly tap the side of a drinking glass with a spoon while filling it with water and you will notice that the pitch of the sound:

decreases (inertia of glass increases, so it slows down the vibrations)

suppose the velocity of waves on a particular rope under a tension of 10N is 12m/s; if tension is decreased to 5N, the speed:

decreases (since the tension decreases, velocity does too)

The net force exerted on a car traveling in a circular path at constant speed is

directed toward the center of the curve

in a resonating pipe which is open at both ends, there are:

displacement antinodes at each end (opposite of string/spring which has displacement nodes at the ends)

in a resonating pipe which is open at one end and closed at the other, there is:

displacement node at the closed end and a displacement antinode at the open end

When the rotational speed of a rotating system doubles, its angular momentum _______.

doubles

Your pet hamster sits on a record player that has constant angular speed. If the hamster moves to a point twice as far from the center, then its linear speed

doubles

Doppler effect occurs when a source of sound moves:

either towards or away from you

A spring wound clock makes use of ___________ energy to drive the mechanism

elastic, spring or Potential

imagine you are holding a long rope under tension attached to a distance support; you can generate periodic waves by shaking the end up and down; changing which of the following will least affect the velocity of waves along string? -frequency -tension -mass/unit length of rope

frequency (v=square root of T/mu we see that frequency does not cause velocity to change)

The pitch of a sound is determined primarily by its

frequency.

A box is pushed across a rough horizontal floor by a force acting parallel to the floor in the direction of motion. A force doing negative work on the body is

friction.

a vibrating guitar string has exactly one antinode and two nodes at the end; you have produced an oscillation of the string at its:

fundamental frequency (fundamental or first harmonic have an antinode in middle with nodes at each end, the second harmonic has a node in the middle and at each end)

musical tone is coming from loudspeaker; if second loudspeaker nearby were to start playing exact same tone, the sound would:

get louder in some areas and softer in others (waves are constructively and destructively interfering depending on where you are)

An ice cube in a glass of water is pushed to the bottom of the glass and held there with a straw. Consequently, the buoyant force on the ice cube is now

greater than when the cube was floating at the top

The carburetor of a car is a pipe with a constriction. Compared to the velocity of flow of a mixture of air and gasoline in the main pipe, the velocity in the constriction will be ______. The pressure in the constriction will be ___________ than the pressure in the main pipe.

greater/less

suppose an audible sound wave were being produced at 800 cycles/s; if frequency were doubled, the sound would become:

higher in pitch (higher frequency means higher pitch)

when two strings on same guitar (same length) are played, two different pitches are heard; comparing the waves on the lower pitch string to the higher, the waves on the higher pitch string have:

higher speed (higher pitched string has lower mass, so it will vibrate more quickly, which allows speed to be higher)

The rotational inertia of an object depends on

how far its mass is distributed from the spin axis.

Suppose you have a helium-filled weather balloon above the house. As a storm approaches the atmospheric pressure drops. Assuming the air temperature is the same, the volume of the balloon will ______________.

increase

Rotational inertia about the midpoint of an object becomes greater with _______.

increased mass and increased distance to mass concentration

If the rotational speed of a rotating habitat in space increases, the weight experienced by occupants

increases

When a twirling ice skater brings her arms inward, her rotational speed

increases

as temperature of air increases, what happens to velocity of sound?

increases

as a wave passes from one medium to another, it often happens that its speed increases with no change in frequency; the wavelength:

increases (v=f*lambda, velocity and wavelength are directly proportional)

two pure tones sounded together and particular beat frequency is heard; what happens to beat frequency if the frequency of one of the tones is increased?

it could either increase or decrease (if the upper frequency is increased, the frequencies get further apart; if lower frequency is increased, frequencies get closer together)

If an object has a larger PE than KE?

its is not possible to predict what the speed will be; depends on the situation

Suppose the momentum of a truck is increased by a factor of 2. If its weight did not change, then

its speed doubled.

A simple machine allows you to move______________masses even though you apply _________

larger; smaller force over a longer distance

If a barometer were to be made using water as the liquid instead of mercury, the length of the barometer tube for water would be _________________than the tube for a standard mercury barometer.

longer

Suppose an audible sound wave were being produced at a frequency of 800 cycles per second. If the amplitude were doubled, the sound would become

louder.

A piece of soft wood floats in water with half of its volume submerged. If it is placed in alcohol which has a density 70% of that of water, it will float __________________ (higher, lower, same) compared with floating in water.

lower

Suppose a little bubble of air has gotten into the top of mercury barometer. If a person uses a barometer in the usual way, the reading of atmospheric pressure will be:

lower than the actual value.

What are the units of measurement for tangential speed? For rotational speed?

m/s for tangential, RPM for rotational

In U.S. customary units, air pressure is measured in "pounds per square inch" (psi). In the metric system, it is measured in "pascals" (Pa), and one pascal is equal to

one newton per square meter.

In U.S. customary units, air pressure is measured in pounds per square inch. In the metric system, it is measured in Pascals, and one Pascal is equal to

one newton per square meter.

trombone or trumpet can be considered an:

open organ pipe

sound source of a high frequency emits a high:

pitch (frequency--measurable or objective--is associated with pitch--subjective)

When a bicycle pedal is at the top of its motion, you can exert the greatest torque on the crank by

pushing straight forward on the pedal with your foot.

When a rock tied to a string is whirled in a horizontal circle, doubling the speed _______.

quadruples the tension in the string

period and frequency of a sound wave are:

reciprocals of each other (f=1/T so if T gets larger, f gets smaller)

compressions and rarefactions normally travel in:

same direction in a wave (compression and rarefactions are normally associated with sound waves)

A ring, a disk, and a solid sphere begin rolling down a hill together. Which reaches the bottom first?

sphere

organ pipe made of wood makes a sound that has a frequency of 450hz when temp is 20C; if temp is 10 colder, the wavelength of sound produced in pipe will:

stay the same (length of the organ pipe doesn't change; the velocity and frequency change)

The rotational inertia of your leg is greater when your leg is

straight

A child blows up a balloon with air. This balloon will not float to the ceiling because

the balloon and the air it contains weigh more than the air displaced by the balloon.

A balloon inflated with helium is able to float toward the ceiling because

the balloon and the gas it contains weigh less than the air displaced by the balloon.

A ball at the end of a string is swinging as a simple pendulum. Assuming no loss in energy due to friction, we can say for the ball that

the potential energy is maximum at each end of the motion.

If you hold a light tissue in your hands and gently blow across its top, the tissue will rise slightly because

the pressure of moving air is less than that of static air.

The skinny tires of a 10-speed racing bicycle require more air pressure than the fat tires on an equally massive mountain bike because

the racing bike touches the ground over a smaller area than the bike with fat tires.

A boat floating in a large pool is loaded with solid iron bars. The water level at the pool's edge is marked with a red line. The iron is now thrown overboard. When the water becomes calm again,

the red line is slightly higher than the water level.

A boat floating in a large pool is loaded with wood blocks. The water level at the pool's edge is marked with a red line. The blocks are now thrown overboard and float outside the boat. When the water becomes calm again,

the red line is still at the water level.

compared to the velocity of a 400hz sound, the velocity of a 200hz sound through air is:

the same (velocity of wave depends on medium; changing the frequency changes wavelength, not velocity)

Two springs are hung from a ceiling and carry identical masses. The first spring has a spring constant twice as large as the second spring. The masses on each spring are pulled down from their equilibrium positions the same distance and are then released. The amplitude of the oscillation is

the same for both springs.

A person wearing snowshoes, an example pictured below, can walk across a blanket of freshly fallen snow without sinking far into the snow because

the snowshoes cover a larger area than a foot and so the pressure is reduced.

If the kinetic energy of an object increases, then

the speed must increase as well.

Consider a system containing three objects that move with different velocities. The objects can interact with each other through forces. In this system

the total momentum of the objects cannot change unless an outside force acts on the system.

An ice cube is floating in a glass of water with the water level just reaching the top of the glass. If the temperature in the surrounding area is above freezing, the ice cube will melt. When it does,

the water level in the glass will remain unchanged as the ice continues to melt.

If there is a net torque on a wheel, then

the wheel must have a nonzero angular acceleration.

Which of the following is not a constituent of mechanical energy?

thermal energy

A robot spacecraft is sent to Mars to explore the Martian polar ice cap. Designers can surround it with a set of inflatable balloons that pop out like automobile air bags as soon as the spacecraft's re-entry parachute opens up.

they increase the time of impact and lessen the stopping force.

A robot spacecraft is sent to Mars to explore the Martian polar ice cap. Designers can surround it with a set of inflatable balloons that pop out like automobile air bags as soon as the spacecraft's re-entry parachute opens up. When the spacecraft lands, it will be able to roll for a few meters across the surface of Mars. The popout balloons have an advantage to the spacecraft, because

they increase the time of impact and lessen the stopping force.

To kick a football so it won't topple end over end, kick it so the force of impact extends

through its center of gravity

For a system in mechanical equilibrium, the resultant

torque must be zero and the force must be zero

A quantity which is conserved in a typical collision of a car and a truck is

total momentum.

An iceberg is floating in the ocean with 10% of its volume extending above the ocean's surface. What can you say about the iceberg?

ts density is 90% that of the ocean water.

Two cylindrical pipes both carry an ideal fluid (zero viscosity) in laminar flow. Pipe A has radius RA = 2 cm and flow velocity vA = 8 cm/s. Pipe B has radius RB = 4 cm and flow velocity vB = 4 cm/s. Compared to the rate of flow in pipe A, that in pipe B is

twice as large.

If you place a pipe over the end of a wrench when trying to rotate a stubborn bolt, effectively making the wrench handle twice as long, you'll multiply the torque by

two

If work was done on an object, the object must have ...

undergone a displacement.

Choose the unit (or combination of units) below which is NOT a correct unit of work.

watt

Which of the following is not an energy unit?

watt

double the frequency of sound and you halve its:

wavelength

To rotate a stubborn screw, it is best to use a screwdriver that has a

wide handle

Which tin can will roll down an incline in the shortest time, one filled with water or one filled with ice? (Hint: water 'slides' inside the can.)

with water

Consider a toy car which is being launched by a compressed spring. Picture shows two possible paths for the car ("path of the car" and "alternate path").

work done by gravity

Consider a toy car which is being launched by a compressed spring. Picture shows two possible paths for the car ("path of the car" and "alternate path"). Choose the quantity below which remains the same for both paths, "path of the car" and "alternate path".

work done by gravity

The PE of a spring is 0.3 Joule when it is COMPRESSED 0.04m to the left of its equilibrium position. At this point it comes to its leftmost position. What is the KE at this point?

zero

Two astronauts of equal mass are holding on to each other and moving together at a speed of 30 m/s. They push off of each other and one of the astronauts moves in the same direction as the two were initially moving but at 60 m/s. The velocity of the second astronaut is

zero.

Choose the correct mathematical relationship below. All symbols have standard meanings: F for force, p for momentum, t for time, x for position, and, as always, Δ for "difference of/in". (Vector notations have been skipped; assume that vector/scalar aspect of the relationship is correct for all expressions below.)

Δ p = F net ⋅ Δ t

Choose the statement below which correctly describes properties of a sound wave.

Sound wave in air is a longitudinal wave of compression and rarefaction of air molecules.

In pole-vaulting, in addition to gravitational Potential Energy there is PE in the bent pole which is analogous to PE stored in __________ under compression

Spring

You hear a musician playing a series of notes of increasing frequency. As the frequency increases, the wave speed

Stay the same

Calculate the torque produced by a 40-N force when a pipe extends the length of the wrench to 0.60 m

T= 24 Nm Torque = Lever Arm × Force

A QUARTERBACK OF MASS 85kg IS RUNNING AT 10m/s. ALSO, A TACKLE OF MASS 100kg IS RUNNING AT 9m/s

THE QUARTERBACK HAS THE GREATER KINETIC ENERGY

On a rotating turntable, how do tangential speed and rotational speed vary with distance from the center?

Tangential speed increases with distance. Rotational speed is constant

Which has the greater kinetic energy? A 2000-kg car moving at 30 m/s or a 1000-kg car moving at 60 m/s?

The 1000-kg car

A body suspended from a spring hanging vertically. The body is them pulled downward so the spring stretches. Consider the change in the elastic potential energy (EPE) of the spring and the change in gravitational potential energy (GPE) as the body is pulled down

The GPE decreases while the EPE increases

A body is suspended from a spring hanging vertically. The body is then pulled downward so the spring stretches. Consider the change in the elastic potential energy (EPE) of the spring and the change in gravitational potential energy (GPE) as the body is pulled down.

The GPE decreases while the EPE increases.

A toy car and a toy truck at rest have a compressed spring in between them. The truck has more mass than the car. The spring is released and the two cars move in opposite directions. Which of the following is true?

The magnitude of the truck's momentum is the same as the car's.

How does the velocity of air moving over the top of the wing of an airplane in flight compare to the velocity of air moving under the wing?

The velocity over the wing is greater.

When work is done by a force on an object, then which of the following is true?

The work done is equal to the change of total kinetic energy of the object plus any additional energy in other forms.

When work is done by a force on an object then which of the following is true?

The work done is equal to the change of total kinetic energy of the object plus any energy appearing as heat, light or sound

If you are not wearing a seat belt in a car that rounds a curve, and you slide across your seat and slam against a car door, what kind of force is responsible for your slide: centripetal, centrifugal, or no force?

There is no force as viewed by someone outside the car. To them you move in a straight line.

How do clockwise and counterclockwise torques compare when a system is balanced?

They are equal in magnitude and opposite in direction

Which of these lists is in order of increasing wavelength?

Third harmonic, second harmonic, first harmonic

Work done in pulling a sled up a hill produces an increase in PE of the sled and rider

This initial energy is converted to KE as they slide down the hill

Consider someone in a rotating space habitat. Rotational motion provides _______.

a support force

Choose the correct description of the rotational phenomenon known as "precession" below.

"Precession" refers to the change in orientation of a spinning object when an external torque acts on the object.

When a baseball bat hits the ball, the impulse delivered to the ball can be increased by

"follow through" on the swing, which increases contact time.

The kinetic energy of a body is correctly given by which of the following expressions (m=mass v=speed)

(1/2)mv2

The kinetic energy of a body is correctly given by which of the following expressions?

(1/2)mv^2

A bullet of mass 0.010 kg and speed of 500 m/s is brought to rest in a wooden block after penetrating a distance of 0.10 m. The work done on the bullet by the block is

-1250 J.

A BULLET OF MASS 0.010kg AND SPEED OF 500m/s IS BROUGHT TO REST IN A WOODEN BLOCK AFTER PENETRATING A DISTANCE OF 0.10m. THE WORK DONE ON THE BULLET BY THE BLOCK IS

-1250 Joule (Energy taken away to slow it down is negative) (W= change in KE= 0 Joules-KE 0 Joule-(1/2mv2)

How can gravity be simulated in an orbiting space station?

-Rotate a cylinder to create centrifugal force as viewed by a person on the inside of the curved outer wall -Spin a station shaped like a bicycle wheel -Spin two pods connected by a cable

A ball of a mass 5 kg attached to a string is swung in a horizontal circle of radius 0.5m If the tension in the string is 10N, the work done by the tension in one revelation is_______

0 (zero)

What is the work done by the vertical component of the force?

0 Joules

Human hearing is most sensitive around 2500 Hz. If the speed of sound is 340 m/s, what is the wavelength of this sound?

0.14 m

The density of ice is about 900 kg/m3 , and the density of water is about 1000 kg/m3. A cubic block of ice one meter on a side floats in water. Assuming that the lowest square face of the cube is horizontal, the height of the block above the water line is:

0.1m

A 1-kg rock is suspended from the tip of a horizontal meterstick at the 0-cm mark so that the meterstick barely balances like a seesaw when its fulcrum is at the 25-cm mark. From this information, the mass of the meterstick is

1 kg

A girl weighs 60 pounds and is sitting on the teeter-totter 3 m from the center. How far from the center should a 180-pound boy sit so that the teeter-totter balances?

1 meter Since the boy weighs three times more than the girl, he needs to be only one-third the distance from the center in order for the torque he exerts on the teeter-totter to balance that of the girl

For a 0.1-kg frog to jump to a height of 1.0 meter requires an energy of about

1.0 Joule (height is potential energy) (PE=m*g*h)

On a day when the speed of sound in air is 340 m/s, what will be the wavelength of sound of frequency 227 Hz?

1.5 m

if you hear thunder 5s after seeing flash of lightning, the distance to the lightning is about:

1.7km (d=vt)

A 30-kg child runs at 3.0 m/s and jumps onto a shopping cart and holds on for dear life. The cart has a mass of 20 kg. Assuming the child rides on the cart after the collision, the speed of the child and shopping cart just after the child jumps on is

1.8 m/s.

According to Bernoulli's equation, the pressure in a fluid will tend to decrease if its velocity increases. Assuming that a wind speed of 1 m/s causes a pressure drop of 0.645 Pa, what pressure drop is predicted by Bernoulli's equation for a wind speed of 4 m/s?

10.32 Pa.

If the atmospheric pressure is about 100,000 N/m2, what is the corresponding downward force on the top of a horizontal square area 10 cm on each side?

1000 N

suppose you sound a 1056hz tuning fork at the same time you strike a note on the piano and hear 2 beats/s; you tighten the piano string very slightly and now hear 3 beats/s; what is the new frequency of the piano string?

1059hz (since you hear 3 beats, the frequency is either 1053 or 1059hz; it started at 1056 and went to 1059 because tightening a string causes the pitch to rise--higher velocity with the same wavelength)

SUPPOSE YOU CLIMB THE STAIRS OF AN EIGHT STORY BUILDING, ABOUT 24m HIGH, AND YOUR MASS IS 70kg. THE GRAVITATIONAL POTENTIAL ENERGY YOU GAIN IS ABOUT

16,500 Joule

Suppose you climb the stairs of an eight-story building, about 24 m high, and your mass is 70 kg. The gravitational potential energy you gain is about

16,800 joules.

What is the total work done by the 50N force?

160 Joules

A force of 50N is used to drag a crate 4m across a floor. The force is directed at an angle upward from the crate as shown. What is the work done by the horizontal component of the force?

160 Joules. (W = F*d)

An 80-kg football player travels to the right at 8 m/s and a 120-kg player on the opposite team travels to the left at 4.0 m/s. The total momentum is

160 kg m/s to the right.

On a day when the speed of sound in air is 340 m/s, a Lightning boot is observed and the resultant thunderclap is heard 5 seconds afterwards. About how far away was the lightning bolt?

1700 m

A child runs at 3.0 m/s and jumps onto a sled, initially at rest. If the child's mass is 36 kg, and if the child and sled slide off together at 2.0 m/s after the collision, the sled's mass is

18 kg.

A gas originally occupies a volume of 0.5 m3 at a pressure of 100 kPa. It is slowly allowed to expand until the volume is 2.5 m3. Assuming the temperature is kept constant, the final pressure will be:

20 kPa.

In a head-on automobile collision, a person's momentum could be reduced from 2000 kg m/s to zero in just 0.1 s. If this occurs, the average force exerted to stop the person during the collision is

20,000 N.

A gas initially is at a pressure of 100 kPa. If its volume is halved while the absolute temperature is kept constant the new pressure will be ___________ kPa.

200

A box is moved 20 m across a smooth floor by a force making a downward angle with the floor, so that there is effectively a 10 N force acting parallel to the floor in the direction of motion and a 5 N force acting perpendicular to the floor. The work done is

200 J.

a BOX IS MOVED 20M ACROSS A SMOOTH FLOOR BY A FORCE MAKING A DOWNWARD ANGLE WITH THE FLOOR, SO THAT THERE IS EFFECTIVELY A 10N FORCE ACTION PARALLEL TO THE FLOOR IN THE DIRETION OF MOTION AND A 5N FORCE ACTING PERPENDICULAR TO THE FLOOR. THE WORK DONE IS

200 Joule (W=F*d)

A painter of mass 70kg climbs 3.0m up a ladder. The painter's potential energy has increased by

2058 Joule (PE=m*g*h)

waves on a particular string travel at 10m/s; a high speed photograph shows that successive peaks are 0.5m apart along the string; the frequency of the waves is:

20hz (v=lambda*f)

A 3.0kg cat runs to left at 10m/s and a 10kg dog runs to the right at 4.0m/s. The total kinetic energy is

230 Joule (KE=1/2mv2)

A 3.0-kg cat runs to the left at 10 m/s and a 10-kg dog runs to the right at 4.0 m/s. The total kinetic energy is

230 joules.

A box is moved 10 m across by a floor a force of 25 N acting along the direction of motion. The work done by the force is

250 J.

A box is moved 10m across by afloor a force of 25N acting along the direction of motion. The work done by the force is

250 Joule (W=F*d)

consider an open pipe of length L; what are wavelengths of the three lowest tones produced by pipe?

2L, L, 2L/3 (wavelength= (2L)/n for a pipe open on both ends)

One section of a pipe carrying water has a cross-sectional area of 20 cm2; in this section the water has flow velocity of 1.0 m/s. Another section of this pipe has a constricted cross-sectional area of 5 cm2. If the flow is steady, what is the water velocity in the constricted section?

4.0 m/s

An object with a kinetic energy of 40 Joule is stopped in a distance of 0.01m. The average force that stops the object is

4000N (F=w/d)

A pendulum swings through 10 cycles in 2 seconds. The frequency of the pendulum is

5 Hz.

tuning fork with frequency of 512hz is used to tune a violin; when played together, beats are heard with 4hz; string on violin is tightened and played again and beats have 2hz; original frequency of violin was:

508hz (original frequency is either 508 or 516; since original is 4hz away from 512. Tightening string will increase frequency and wavelength doesn't change so since v goes up, f goes up; since the beat frequency is going down, it means that the frequencies are getting closer together; so it has to be the lower beat frequency)

If the atmospheric pressure is 15 lb/in2 , what is the corresponding downward force on the top of a horizontal square area 6 inches on each side?

540 lbs

A pendulum swings through 10 cycles in 2 seconds. The frequency of the pendulum is

5Hz Frequency= (Hz=cycles/second)

period of second hand on a clock is:

60s (period is time to make it around once to it's original position)

A hydraulic jack is used to lift a load of weight 1000 N. The load-bearing cylinder has a radius of 4 cm, and the other piston has a radius of 1 cm. What force must be exerted on the smaller piston to support the load?

62.5 N

If you're on a Ferris wheel at a carnival, seated 10 m from the Ferris wheel's axis that makes a complete rotation each minute, your linear speed is

62.8 m/min

An ice cube in a glass of water is pushed to the bottom of the glass and held there with a straw. Consequently, the buoyant force on the ice cube is now

An ice cube in a glass of water is pushed to the bottom of the glass and held there with a straw. Consequently, the buoyant force on the ice cube is now

Distinguish between linear momentum and angular momentum

Angular momentum depends on the distribution of mass, whereas linear momentum depends on the total mass

What is the law of inertia for rotating systems in terms of angular momentum?

Angular momentum does not change without an applied external torque

W= F*d

Answer will be in Joules

Jim exerts a force of 500N against a 100kg desk that does not move. Virgil exerts a force of 400N against a 60kg desk that moves 2m in the direction of the push. Mik exerts a force of 200N against a 50kg desk that moves 4m in the direction of the push. The most work is done by A.) Mik B). Virgil and Mik, who do equal amounts of work C.) Virgil D.) Jim

B). Virgil and Mik, who do equal amounts of work W = F * D Jim Work: 500 * 0 = 0 J Virgil Work: 400 * 2 = 800J Mik Work: 200 * 4 = 800J

Which of the following is not an energy unit A). Energy B). Watt C). kWh D). Joule E). Nm

B). Watt Watt is a unit of power.

Which has the greater kinetic energy - a 1 ton car moving at 30m/s or a half ton car moving at 60ms? A.) A 1 ton car B). A half-ton car C.) both have the same K.E

B). half-ton car KE(1 ton car) = 1/2 * 1000 * 30^2 = 450,000J = 450KJ KE(.5 ton car) = 1/2*500*60^2 = 900,000J = 900J

A baseball bat can be rotated around many different axes of rotation. Three such possibilities are shown in (Figure 1) . Rank the baseball bat's moment of inertia about each of these three axes of rotation

B, A, C Because the total mass is the same for all three axes, only the distribution of that mass changes the moment of inertia. All of the mass is close to axis C, so that the axis has the smallest moment of inertia. The bulk of the mass (in the meat of the bat) is further from axis B than A; therefore, axis B has the largest moment of inertia

The kinetic energy of a body is correctly given by which of the following expressions A.) 1/2, mv B.) 1/2, mv^2 C.) mv D.) mv^2 E.) 2 mv^2

B.) 1/2, mv^2 KE = 1/2mv^2

A child runs at 4.0 m/s and jumps onto a sled intially at rest. If the child's mass is 36kg and if the child and sled slide off together at 3.0 m/s after the collision , the sled's mass is A.) 48kg B.) 12kg C.) 36kg D.) 27kg

B.) 12kg Ptotal Intial = Ptotal Final Pki + PSi = Pksf MkVk +MsVsi = (Mk + Ms) Vf 36 * 4 = ms + 0 = (36 + ms) * 3 144 + 0 = (36 + ms) * 3

Suppose you climb the stairs of a ten story building about 30M high and your mass is 60kg. The gravitational potential energy you gain is about A.) 27000J B.) 18000J C.) 1800J D.) 270J

B.) 18000J PE = MGH = 60 * 9.8 * 30 = 17640 ~ 18000J

Which of the following is not a unit of power A.) Horsepower B.) Kilowatt-Hour C.) Watt D.) Joule/Second E.) Kilowatt

B.) Kilowatt-Hour Kilowatt hour is electrical energy unit

Two people sit face to face on chairs which are free to roll without any friction. They push each other with a force of 50N and move apart. Person A whose mass including the chair is 80kg, moves to the left at 2.5m/s. Person B whose mass including the chair is 50kg A.) Moves to the right at 10 m/s B.) Moves to the right at 4 m/s C.) Moves to the right at 3.16 m/s D.) Moves to the right at 2.5 m/s

B.) Moves to the right at 4 m/s Ptotal(intial) = Ptotal(final) Pai + Pbi = Paf + Pbf 0+0 = 80 * (-2.5) + 50 * vbf 50vbf = 200 vbf = 4m/s to the right

One form of the proper metric unit for for momentum is A.) Kg m B.) N Sec C.) Joule D.) Kg m/s^2

B.) N Sec Force * Time = Momentum Unit Newton * Second

Work done on an object to increase its total energy. Which of the following is true?

Both the KE and PE energy can be larger

A bowling ball moving to the east at a speed of 1.4 m/s collides head-on with a stationary beach ball of the same diameter but less than one twentieth the mass after the collision the beach ball moves with a speed of 1.6 m/s which of the following is true then? A.) The beach ball has more momentum than the bowling ball B.) The bowling ball has a velocity of slightly under 1.4 m/s to the east C.) The bowling ball and the beach ball have the same momentum after the collision D.) The bowling ball recoils to the west with nearly the same speed as before.

B.) The bowling ball has a velocity of slightly under 1.4 m/s to the east Momentum is conserved.

A quaterback of mass 85kg is running at 10m/s. Also a tackle of mass 100kg is running at 9m/s A.) The tackle has the greater kinetic energy B.) The quarterback has the greater kinetic energy C.) The quarterback and tackle have equal kinetic energies

B.) The quarterback has the greater kinetic energy KE = 1/2mv^2 Q: 1/2 * 85 * 10^2 = 4,250J T: 1/2 * 100 * 9^2 = 4,050J

When work is done by force on an object , then which of the following are true? A.) The object does negative work on the force B.) The work done will be equal to the change of the total energy of the object plus energy appearing as heat, light, sound C.) The energy lost to friction is equal to the amount of work done by the force D.) The mass of the object always increases E.) The speed of object always increases

B.) The work done will be equal to the change of the total energy of the object plus energy appearing as heat, light, sound Work = Change in K.E

Other things (density, altitude, temperature) being equal, a moving gas exerts less pressure than a stationary gas. This is predicted by _______________________ (2 words).

Bernoulli's equation

Given the same baseball bat and possible axes of rotation shown in (Figure 1) , for which axis of rotation would it be the easiest to rotate the bat from rest?

C (the end) The smaller the moment of inertia of an object, the easier it is to change its state of rotation

Intially, a blue automobile has twice the KE that a red automobile has. Both are braked to a stop; both have the same amount of braking force. The red auto will stop in ____________________ as the blue auto. A.) One fourth the distance B). The same distance C). Half the distance D.) Four times the distance E.) Twice the distance

C). Half the distance

A 5.0kg cat runs to the left at 10m/s and a 10kg dog runs to the right at 5.0m/s. The total kinetic energy is A.) 500J B.) 0 C.) 375J D.) -125J E.) 100J

C.) 375J Energy has no direction then total kinetic energy = KE total KE Total = KE(Cat) + KE(Dog) KE = 1/2mv^2 KE Total = (1/2*5*10^2) + (1/2*10*5^2) = 250 + 125 = 375J

An object with a kinetic energy of 50J is stopped in a distance of 0.01m. The average force that stops the object is A.) 50,000N B). 50N C.) 5,000 N D.) 0.5N E.) 500N

C.) 5,000 N F * D = Change in KE = KE(inital) - KE (final) F * 0.01 = -50 0.01F = - 50 F = 50/0.01 = 5,000N

In attempt to pull a 1500 kg car out of a ditch , Al exerts a force of 200N for 5s, Bill exerts a force of 500N for two s, and Clyde exerts a force of 300N for 4 seconds . The car does not move at all who has the greatest impulse. A.) Al B.) Bill C.) Clyde D.) Al, Bill and Clyde provide equal, indeed zero, impulse.

C.) Clyde Impulse = Force * Time Al: 200 * 5 = 1000Ns Bill: 500 * 2 = 1000Ns Clyde: 300 * 4 = 1200Ns

A box is pushed eastward across a rough horizontal floor by a force acting parallel to the floor. A force providing an impulse directed westward on the body. A.) Gravity B.) Normal reaction for of the floor upward on the body C.) Friction D.) The applied force E.) The fictious force

C.) Friction Rough Surface => Friction; which opposes direction of motion.

A box is pushed across a rough horizontal floor by a force acting parallel to the floor in the direction of motion. A force doing no work during the motion is A.) The applied force B.) Friction C.) Gravity

C.) Gravity The box is not moving in the vertical direction

Which of the following mathematical expressions should be used to calculate the momentum of an auto? A.) Weight x Speed B). Weight x Force C.) Mass x Velocity D.) Mass x Acceleration?

C.) Mass x Velocity P= Mv

A refrigerator weighing 1500N is to be lifted onto a truck bed that is 1.0m above the ground. When pushed up a slanting ramp 2.0m in the length a force of only 800N is required to move it at constant velocity. Comparing the work involved in lifting the fridge straight up to the work in pushing it along the ramp, there is A.) An equal amount of work is required in each case B.) Less work required when the ramp is employed C.) More work required when the ramp is employed

C.) More work required when the ramp is employed Work = Force * Distance Straight Up = 1500 * 1 = 1500J Ramp = 800 * 2 = 1600J

A ping pong ball is dropped vertically onto a stationary bowling ball resting on the floor. Which of the balls experiences the greater force as a result of the collision A.) The ping pong ball B.) The bowling ball C.) Neither, both experience forces of the same size D.) It is impossible to tell from this data.

C.) Neither, both experience forces of the same size Newton's 3RD Law

Suppose you are out on a frozen lake , where there is no friction. Which one of the following would start you moving towards the shore? A.) Shouting at someone on the shore B.) None of these would work C.) Removing a shoe and throwing it away from shore D.) Removing a shoe and throwing it to shore.

C.) Removing a shoe and throwing it away from shore

A grandfather clock that is regulated by a pendulum is taken to the Moon where the acceleration of the gravity is less. Compared to an indentical clock on earth the grandfather clock on the moon will A.) Keep time at the same rate B.) Run fast C.) Run slow

C.) Run slow MGH = 1/2mv^2 G on the moon less than G on Earth PE Moon < PE Earth KE Moon < KE Earth

The power of an engine is the measure of A.) It's ability to outperform a horse B). The total amount of work it can preform C.) The rate at which it can preform work D.) It's volume

C.) The rate at which it can preform work Power = Work/Time

A tennis ball bounces off a brick wall. Which of the following is true? A.) The momentum of the ball is conserved in this process B.) If the collision is elastic , then the ball's velocity does not change in this process C.) The total momentum of the ball, wall and earth is conserved in the process D.) None of these are true

C.) The total momentum of the ball, wall and earth is conserved in the process Total momentum is conserved in any collision

A worker in a warehouse uses a rope passing through some pulleys to lift a heavy crate. The worker exerts a force five times less than the weight of the crate by has to move the rope four times as far as the crate moves This situation?

Cannot happen because the work done by the worker is less than the work done on the crate.

A worker is a warehouse uses a rope passing through some pulleys to life a heavy crate. The worker exerts a force five ti,es less than the weight of the crate but has to move the rope four times as far as the crate moves. This situation

Cannot happen because the work done by the worker is less than the work done on the crate. (needs to be equal)

If work was done on an object the object must have?

Changed its position

If work was done on an object, the object must have

Changed its position

Choose the physical principle listed below which is most closely related to Bernoulli's Principle.

Conservation of Energy

Total mechanical energy of a system is conserved when there are only _____________ forces doing work on the system

Conservative

A box is moved 10 m across a smooth floor by a force making a downward angle with the floor so that there is effectively a 10N force acting parallel to the floor in the direction of motion and a 5N force acting perpendicular to the floor. The work done is A.) 5.0J B.) 50J C.) 150J D.) 100J E.) 10J

D.) 100J Work = Force Parallel * Distance W = 10 * 10 = 100J

In a head on automobile collision, a person's momentum could be reduced from 2,000 kg m/s to zero in just 0.1 s. If this occurs, the average force exerted to stop the person is A.) Can't answer the question without knowing person's mass B.) 200 N C.) 2,000N D.) 20,000N

D.) 20,000N Impulse = Change in momentum F * T = Pf - Pi F * I = 0 - 2000N F = -2000N

A 20N ball and a 40N ball are dropped at the same time from a height of 10M. Air resistance is negligible. Which of the following statements are accurate. A.) The heavy ball has a greater acceleration and falls faster B.) The light ball has a greater speed since it can accelerate faster than the heavy ball C.) After 1 second has elapsed, both balls have the same kinetic energy since they have the same acceleration D.) Both balls hit the ground at the same time but gravity does more work on the heavy ball than on the light ball.

D.) Both balls hit the ground at the same time but gravity does more work on the heavy ball than on the light ball. More Mass = More Energy

The momentum of a truck is increased by a factor of 4. It's weight does not change, thus A.) It's acceleration doubled B.) It's kinetic energy doubled C.) It's speed doubled D.) It's speed increased by a factor of 4

D.) It's speed increased by a factor of 4

A gun is made of a super low weight but strong material the bullet for the gun is more massive than the gun itself. For such a gun A.) Recoil problems would be lessened B.) The bullet would go farther with less power C.) Conservation of momentum is not satsified D.) The gun if unsupported would have a recoil velocity higher than bullet velocity

D.) The gun if unsupported would have a recoil velocity higher than bullet velocity In case of recoil => Less mass = High Velocity

A ball at the end of a string is swinging as a simple pendulum. Assuming no loss in energy due to the friction we can say for the ball that A.) The potential energy is maximum where the kinetic energy is maximum B.) The kinetic energy is maximum at each end of the motion C.) The potential energy is maximum at the lowest position of the ball D.) The potential energy is maximum where the kinetic energy is a minimum

D.) The potential energy is maximum where the kinetic energy is a minimum

A quantity which is conserved in the collision of a car and a truck is? A.) Nervous energy B). Momentum of the truck C.) Momentum of the car D.) Total Momentum E.) Kinetic Energy

D.) Total Momentum As general collision => Conservation of momentum inelastic or elastic collision.

A 5.0kg cat travels to the left at 10m/s and a 10kg dog travels to the right at 5.0m/s. The total momentum is A.) 100kg m/s to the right B.) 125kg m/s to the left C.) 50kg m/s to the right D.) Zero

D.) Zero Momentum is a vector.

A wooden block slides down a rough incline which of the following statements is true. A.) The mechanical energy of the block is constant B.) The mechanical energy of the block is increasing C.) The gravitational potential energy of the block is increasing D.) The kinetic energy of the block is decreasing E.) The mechanical energy of the block is decreasing

E.) The mechanical energy of the block is decreasing Rough Surface = > Friction Force As block slides down => -Ve work due to friction => Mechanical energy decreases.

A block sits on a slight incline, held at rest by the frictional force between the block and the incline. Which of the following statements is true? A.) The frictional force preforms no work since there is no motion of the block B.) The work done by gravity is entirely converted into heat because of the friction present C.) None of these are true D.) The work done by the frictional force is negative since the force of friction opposes the direction of the block is being tugged by gravity E.) The work by the frictional force is equal to the gravitational potential energy of the block

E.) The work by the frictional force is equal to the gravitational potential energy of the block

Fnet =

F-f (Force minus friction)

Calculate the tension in a horizontal string that whirls a 1.9-kg toy in a circle of radius 2.0 m when it moves at 2.9 m/s on an icy surface

F= 7.98N Centripetal Force: F=mv^2/r

A CHILD RIDING ON A SWING RISES TO HEIGHT 1.0m ABOVE THE LOWEST POINT. ANOTHER CHILD OF EQUAL MASS WHOSE SPEED AT THE LOWEST POINT IS TWICE AS GREAT WILL RISE

FOUR TIMES AS HIGH

A child riding on a swing rises to a height 1.0m above the lowest point. Another child of equal mass whose speed at the lowest point is twice as great will rise?

Four times as high

Suppose Sally lived on the equator of a planet that had a radius twice that of Earth's radius and that rotated with twice the angular velocity (so one day would be 12 hours long). Sally's speed on this planet would be _______ Joe's speed (who lives on Earth's equator).

Four times faster than Since Sally's angular velocity is twice as high as Joe's, and since Sally is tracing out a circle with twice the radius of Joe's path, Sally is going four times faster than Joe

The Doppler effect refers to changes in a sound wave's

Frequency coused by motion of a source or receiver

A box is pushed across a rough horizontal floor by a force acting parallel to the floor in the direction OF MOTION. A force doing NEGATIVE WORK on the body is

Friction

A box is pushed across a rough horizontal floor by a force acting parallel to the floor in the direction of motion. A force doing negative work on the body is?

Friction

A horizontal force acts on a block that is initially at rest but free to move across a smooth horizontal surface. The work done by this force __________ the kinetic energy of the block

Increases

How does the force needed to turn the wrench change if you increase the lever arm?

It decreases

How does the lever arm change if you decrease the angle of the force?

It decreases

How does the lever arm change when you decrease the distance to the nut?

It decreases

Why is centrifugal force in a rotating frame called a "fictitious force"?

It is not a fundamental force of nature. Instead, it is a force that only appears in an accelerating frame of reference

If an object has a larger PE than KE

It is not possible to predict what the speed will be, it depends on the situation

What is meant by the "lever arm" of a torque?

It is the perpendicular distance from the rotational axis to the line along which the force acts

A girl spins around in a circle trying to make herself dizzy. Without changing her position, she starts spinning twice as fast. By how much did her rotational kinetic energy change?

It quadrupled -because rotational kinetic energy is given by the equation Krot = 12Iω2

A brick slide across a horizontal rough surface and eventually comes to a stop. What happened to the kinetic energy of the brick?

It was converted to other energy forms, mostly heat

Does the normal force of the floor pushing upward on the block do any work?

NO, the normal force does no work.

The principle that total momentum does not change during a brief collision is a result of

Newton's second law and Newton's third law.

If the string that holds a whirling can in its circular path breaks, what kind of force causes it to move in a straight- line path: centripetal, centrifugal, or no force? What law of physics supports your answer?

No force; Newton's first law

Can the gravitational force of Earth do positive or negative work on a geosynchronous communication satellite, once it is on its circular orbit?

No, because the force is always perpendicular to the orbital path

Can the gravitational force of Earth do positive or negative work on a geosynchronous communication satellite, once it is on its circular orbit?

No, because the force is always perpendicular to the orbital path.

A grandfather clock that is regulated b a pendulum is taken to the Moon, where the acceleration of gravity is less. Compared to an identical clock on Earth, the grandfather clock aboard the space station will?

Not run at all

A string is used to pull a wooden block across the floor without accelerating the block. The string makes an angle to the horizontal. Does the force applied via the string do work on the block?

Only horizontal part of the force F does the work

Power is the rate of doing work Power = Work divided by Time

P = W/t (answer will be in Watts)

Choose the correct formula for the pressure due to weight of fluid.

P=ρgh

Choose the correct formula for the pressure due to weight of fluid. Symbol key: ρ stands for density; h stands for height of fluid; v stands for fluid velocity; V stands for volume; P stands for pressure. All other symbols ( g , etc.) are used in the standard sense we have been using in mechanics.

P=ρgh

If work is done but no kinetic energy is gained, we say that the POTENTIAL ENERGY has increased

PE = mass x gravity x height

The fact that an increase of pressure on an enclosed fluid is transmitted uniformly throughout the fluid is ______________ Law.

Pascal's

The operation of a hydraulic jack is based upon _______________ Law.

Pascal's

The ______ of a pendulum is the amount of time the pendulum takes for one full swing

Period

=A spring would clock make use of _____ energy to drive the mechanism.

Potential

Consider each situation described below. In which situation is the angular momentum of the specified system not conserved?

Precession of a bicycle wheel spinning vertically at a constant speed (system: bicycle wheel)

The period and the frequency of a sound waves are

Reciprocals of each other

A bowling ball, moving to the east at a speed of 1.4 m/s, collides head-on with a stationary beach ball of the same diameter but less than one twentieth the mass. After the collision, the beach ball moves with a speed of 1.6 m/s. Which of the following is then true?

The bowling ball has a velocity of slightly under 1.4 m/s, to the east.

Inertia depends on mass; rotational inertia depends on mass and something else. What?

The distribution of mass about the axis of rotation

An ant and an elephant are walking through the jungle. On which does the greater buoyant force act?

The elephant.

On a frictionaless tabletop, a force is applied to an object: the object velocity is horizontal and the force is perpendicular to the tabletop. Which of the following is true?

The force does work on the object

A guitar is perfectly tuned. The tension on its strings is then increased, increasing the speed of the wave on the string. Which of the following is true?

The frequencies of sounds from the guitar are higher than before.

A block sits on a slight incline heat at rest by the frictional force between the block and the incline. Which statement is true?

The frictional force performs no work, since there is no motion of the block

A block sits on a slight incline, held at rest by the frictional force between the block and the incline. Which of the following statements is true

The frictional force performs no work, since there is no motion of the block

A block sits on a slight incline, held at rest by the frictional force between the block and the incline. Which of the following statements is true?

The frictional force performs no work, since there is no motion of the block.

Which has the greater kinetic energy---a 1-ton car moving at 30m/s or a half-ton car moving at 60m/s

The half ton car

A helium inflated balloon and an air inflated balloon are placed inside a van. The van doors and windows are closed. While the helium balloon is at rest near the ceiling and the air balloon is at rest on the floor, the van driver suddenly accelerates forward. What happens?

The helium balloon moves to the front while the air balloon moves to the rear.

Suppose a ball is dropped from shoulder height, falls, makes a perfectly elastic collision with the floor, and rebounds to shoulder height. Compare the magnitudes of the impulses delivered to the ball by gravity during the drop and by the floor during the elastic collision.

The impulse delivered by the floor is twice as large as the impulse delivered by gravity during the drop.

Choose the statement below which correctly defines or describes nodes and antinodes.

The positions of nodes and antinodes do not change over the cycle of the wave.

A ball at the end of a string is swinging as a simple pendulum. Assuming no loss in energy due to friction, we can say for the ball that

The potential energy is maximum at each end if the motion

A ball at the end of a string is swinging as simple pendulum. Assuming no loss in energy due to friction, what can say for the ball that?

The potential energy is maximum, at each end of the motion

The power of an engine is measured of?

The rate at which it can perform work

The power of an engine is a measure of

The rate at which it can perform work (P=w/t)

Which will have the greater acceleration rolling down an incline: a hoop or a solid disk? Why?

The solid disk will because the mass is closer to the axis of rotation

A solid sphere and a hollow sphere (spherical shell) of the same mass and same radius rotate with the same amount of kinetic energy. Which one is rotating faster?

The solid sphere Because the rotational kinetic energy is given by the equation Krot = 12Iω2, the object with the smaller moment of inertia would have to spin faster to obtain the same value for the rotational kinetic energy. The hollow sphere is just like the solid sphere, except that you would take the mass near the axis for the solid sphere and shove it outwards towards the surface. Moving mass further from the axis of rotation makes the moment of inertia for the hollow sphere larger than the solid sphere.]

If the KE of an object increases, then

The speed must increase a s well

A tapered cup rolled on a flat surface makes a circular path. What does this tell you about the tangential speed of the rim of the wide end of the cup compared with that of the rim of the narrow end?

The tangential speed of the wide end is faster

On a friction-less tabletop, a force is applies to an object: the objects velocity is horizontal and the force is perpendicular to the tabletop. Which of the following are true?

The total energy of the object does not change

A tennis ball bounces off a brick wall. Which of the following is true?

The total momentum of the ball, wall, and Earth is conserved in this process.

What does a torque tend to do to an object?

Torque tends to twist or change the state of rotation of the object

When you whirl a can at the end of a string in a circular path, what is the direction of the force you exert on the can?

Toward the center of the circle

Electromagnetic waves are generally

Transverse waves

In order for a body to exhibit simple harmonic motion there must be

a force drawing the body toward the center and increasing with distance away from the center.

A sharp knife can more easily cut objects than can a dull knife because

a greater pressure can be applied with a sharp knife.

A racquetball is dropped from a height of one meter. It bounces off the floor and rises to a height of 0.8 m. The collision with the floor was

a partially inelastic collision.

In each of the situations below, two or more forces act on the object (or person) described. Net work is defined as the total work done by all the forces acting on the object. Choose the situation in which some net work is done.

a shopping cart is accelerated from rest to 3 m/s

Which of the following is a longitudinal wave?

a sound wave in air

The rotational inertia of a pencil is greatest about an axis

about its end, like a pendulum

The famous Leaning Tower of Pisa doesn't topple over because its center of gravity is

above a place of support

some of a wave's energy dissipates as heat; in time, this will reduce the wave's:

amplitude (energy is associated with amplitude)

loudness of a musical sound is a measure of the sound wave's:

amplitude (measurement of energy comes from the amplitude)

Archimedes Principle states that

an object immersed in a fluid is buoyed up by a force equal to the weight of the displaced fluid.

Archimedes' Principle states that...

an object immersed in a fluid is buoyed up by a force equal to the weight of the displaced fluid.

One morning you discover that a tire on your auto is in need of air. This is visible: it has flattened significantly. Significant flattening indicates low air pressure

because more of the tire's surface area is required to provide same amount of force.

A dancer begins performing a pirouette with arms extended. (A pirouette is a complete spin about a vertical axis.) This motion is completed most easily when the rotational inertia is decreased by

bringing the arms and legs in a line with the body.

you're standing on sidewalk and there is a car in the distance that lays on the horn and you hear it at a pitch that corresponds to sound frequency lower than the frequency emitted; what can you conclude?

car has a component of its velocity in a direction away from you (it doesn't have to be moving directly away to get the effect; wind does not change medium; any component of velocity moving away from you will give you a decreased frequency)

Which of the following does NOT describe a system that can undergo simple harmonic oscillator motion?

cart on an inclined ramp

Toss a baseball bat into the air and it wobbles about its

center of mass

The bigger diameter gears on the rear wheel of a multi-speed bike allow the rider to

exert more torque on the wheel.

bats use infrasound to navigate: T or F

false

Consider a string with several rocks tied along its length at equally spaced intervals. You whirl the string overhead so that the rocks follow circular paths. Compared with a rock at the end of the string, a rock at the middle moves

half as fast

Hot coffee is poured into a cylindrical container until it is nearly full. The container is immediately sealed by stretching a rubber balloon across the container mouth and tightly sealing the edges. Twenty minutes later, you observe that the still intact rubber seal

has sagged inward toward the coffee.

to change the fundamental frequency of a guitar string, you can:

make it shorter, by pressing a finger of your left hand on the string (fretting a guitar string shortens the wavelength without changing the medium, so since the length goes down, frequency goes up)

Which of the following mathematical expressions should be used to calculate the momentum of an automobile?

mass × velocity

consider possible standing wave patterns for a string fastened at each end; discussion in text shows that there is a:

maximum possible wavelength (as you go into higher harmonics, the wavelength gets smaller and frequency higher; in theory, you could continue forever; also, you could keep making the amplitude in theory)

node is a position of:

minimum amplitude (nodes have no movement; antinodes have maximum movement)

A solitary boy cannot balance on a seesaw with its fulcrum at its midpoint. If the fulcrum is moved to one-quarter the distance from the boy, balance is achieved when the weight of the boy is

more than the weight of the seesaw

Two people sit face to face on nice skateboards at rest that are free to roll without friction. They push each other with a force of 40 N and move apart. Alice, whose mass (including the skateboard) is 50 kg, moves to the left at 3 m/s. Bob, whose mass (including the skateboard) is 60 kg,

moves to the right at 2.5 m/s.

A ball that gains speed as it rolls down a hill experiences a

net force and net torque

The angular momentum of a rotating body is conserved when

no net torque acts on the body.

double the frequency of sound and you also double its: -wavelength -speed -amplitude -all -none of these

none of these (velocity stays same and wavelength halves)

If a force acts on an object for some time, the impulse will be

nonzero in all situations.

a 1056hz tuning fork is sounded at the same time a piano note is struck; you heart 3 beats/s; what is frequency of piano string?

not enough information to be certain (it could be 1053 or 1059hz)

wave travels an average distance of 1m in 1s with 1Hz; amplitude is:

not enough information to say (v=f*lambda; amplitude is not dependent on these things)

A grandfather clock that is regulated by a pendulum is orbiting the Earth aboard the space station. Compared to an identical clock on Earth, the grandfather clock aboard the space station will

not run at all

A mass hangs on a spring held in a physicists hand. When the mass is pulled sown and the released, it oscillates with a period of 2.0 s. This system is taken to the Moon, where the acceleration of gravity is less. The spring on the moon is held in an astronauts hand, and the mass, when pulled down and released, will

oscillate with an unchanged period

A mass attached to a spring is drawn back 2 cm from equilibrium and released. If a second spring were used that had a smaller spring constant than the first but the mass was the same, which of the following would be larger, if it is also drawn back 2 cm from equilibrium and released?

period

A ring and a disk both at rest roll down a hill together. Which rolls slower?

ring

Two people are balanced on a seesaw. If one person leans inward toward the center of the seesaw, that person's end of the seesaw tends to

rise

If you were standing on a cart that was at rest and free to roll (ignore friction) and someone threw a 10 kg ball at you, you would

roll backward faster if the ball bounced off of you elastically.

As a huge rotating cloud of particles in space gravitate together forming an increasingly dense ball, it shrinks in size and

rotates faster

Centrifugal forces are an apparent reality to observers in a reference frame that is

rotating

A torque acting on an object tends to produce

rotation

A grandfather clock that is regulated by a pendulum is taken to the moon, where the acceleration of gravity is less compared to an identical clock on Earth, the grandfather clock on the moon will

run slow

A penny, a quarter and a silver dollar lie at the bottom of a wishing well filled with water. The coin experiencing the largest downward force on its top surface due to the water pressure is the:

silver dollar

The chef at the infamous Fattening Tower of Pizza tosses a spinning disk of uncooked pizza dough into the air. The disk becomes wider during its flight, while its rotational speed

slows

A uniform wooden plank floats in a swimming pool. The plank weighs 100 pounds, and exactly 10% of its volume is above the waterline. The maximum weight of iron which could be suspended from underneath the plank without causing the whole combination to sink to the bottom of the pool is

somewhat more than 10 pounds.

which of the following is a longitudinal wave? -light wave -wave on string under tension -sound wave in gas -none -all

sound wave in gas (sound waves are compression)

Three individuals stand with all of their weight on the heel of one foot: a man of weight 600 N and a heel area of 100 cm2, a child of weight 200 N and a heel area of 25 cm2, and woman of weight 450 N and a heel area of 2 cm2. The one exerting the least pressure on the ground is

the man.

Three individuals stand with all of their weight on the heel of one foot: a man of weight 600 Nandaheelareaof100cm2,achildofweight200Nandaheelareaof25cm2 andwomanof weight 450 N and a heel area of 2 cm2. The one exerting the least pressure on the ground is:

the man.

If a single force acts on a moving object for some amount of time,

the momentum of the object must change.