PHYS 105 Exam #2
A weightlifter lifts a weight a height of 0.6 m directly upward very slowly. Considering gravitational force is one way to reconcile the results in (a) and (b) above. How much work is done by gravitational force on the weight? (Note: Be mindful of the direction of the force relative to displacement. Negative work done reduces kinetic energy, while positive work done increases kinetic energy.)
-180 J
A weightlifter lifts a weight a height of 0.6 m directly upward very slowly. What is the net work done in the weight by all forces on it?
0 J
The audible range of sound wavelengths in air range between ______ and ____ meters
0.0172; 17.2
A shopper pushes a 30 kg cart over 1.2 meters, pushing w/ a force of 12 Newtons. It turns out that the shopping cart does not roll frictionlessly, but instead there is a friction force of 9 newtons. What is the speed of the cart at the end of the push?
0.489 m/s
How fast does a 3300 kg elephant need to move, in order to have the same kinetic energy as the sprinter?
1.23 m/s
The shopping cart rolls down a ramp starting from rest, and as it rolls down, the gravitational force does 29 joules of work on the cart. What is the speed of the cart at the bottom of the ramp, if you can ignore friction?
1.38 m/s
Suppose on a stormy night, you see a lightning flash then hear the sounds of thunder about 5.5 seconds later. How far away do you estimate that the lightning struck?
1.87 km away
A satellite in a geosynchronous orbit moves at a speed of 3075 m/s. If the mass of the satellite is 3500 kg, the momentum of the satellite is _________ x 10^6 kg x m/s
10.7
Sometimes, we don't know the forces involved in the interaction, but instead, we know the initial and final velocities of the objects involved in the interaction. Consider baseball for example. Suppose a batter hits a fastball approaching at 44 m/s and the ball flies away at 50 m/s. The mass of a baseball is 0.145 kg. What is the magnitude of the impulse delivered to the baseball by the bat?
13.63 kilogram x meter/second
Calculate the work done on a crate pushed 3.1 m up along a ramp. The man exerts a force of 440 N on the crate parallel to the ramp, and the crate moves at a constant speed.
1364 joules
A weightlifter lifts a weight a height of 0.6 m directly upward very slowly. If the weight weighs 300 N, how much work is done by the weightlifter?
180 J
Give below the low end and upper end of the range of frequencies as a comma-separated ordered list of numbers (give the low end first).
20; 20,000
What is the kinetic energy of a 62 kg sprinter sprinting at 9 m/s?
2511 joules
Suppose that the D string of a guitar vibrates at 148 Hz (it's a bit out of tune) for the fundamental frequency. What are the frequencies of the next two harmonics? Give your answer as a list of two numbers, separated by a comma below.
296,444 Hz
A delivery driver lifts a package of mass 5 kg by a height of 0.7 m to load it into a truck. Answer below questions. Use approximate value of gravitational acceleration g≈10 m/s^ 2 in this question. By how much did the gravitational potential energy of the package increase?
35 J
Suppose that the mass of the bullet for a pistol is 9 grams, and when fired, the bullet exits the pistol muzzle with a velocity of 350 m/s. If the mass of the pistol is 700 grams, what is the would-be recoil velocity of the pistol, if it is free to move backward?
4.5 m/s
An automobile (of mass 1600 kg) speeds down a freeway at a speed 68 mph (which you will need to convert to meters per second). What is the momentum of this automobile?
48640 kg x m/s
Study of olympic boxers show that punch of a boxer can produce a force in the range of 3300 newtons. If the contact of the punch lasts 0.15 second (about half of typical human reaction time), estimate the impulse delivered by a boxer's punch.
495 newton x second
A runner of mass 67 kg runs at a speed 8 m/s (17.9 mph). The momentum of this runner is ______ kg x m/s
536
A shopper pushes a grocery cart 20.8 m at a constant speed on level ground. If the shopper pushes with 30-N force, how much work is done by the shopper?
624 J
What is the formula for rotational kinetic energy?
KE = 1/2Iw^2
Kinetic energy equation
KE=1/2mv^2
A rotating object will continue to rotate unless acted on by a net torque
Newton's 1st Law
Angular acceleration of an object is proportional to net torque and inversely proportional to rotational inertia
Newton's 2nd Law
For every torque applied by Object A on Object B, there is a torque of equal magnitude and opposite direction applied by Object B on Object A
Newton's 3rd Law
What is the formula for the pressure due to weight of fluid?
P = pgh
Spring Potential Energy Equation
PEel = 1/2kx^2
gravitational potential energy equation
PEg = mgh
work done by a force equation
W = Fd
Watching a pendulum swing back and forth, you observe it swinging back and forth 8x over a time of 6 seconds. What is the period of the pendulum? a. 0.8s b. 2.3s c. 8s d. 1.9s e. 6s
a. 0.8s
Kinetic energy of a 18000 kg truck moving at 38 m/s is (a)_____ x 10^6 joules and the kinetic energy of a 70 kg astronaut moving in orbit at 6200 m/s is (b)_____ x 10^9 joules. Comparing kinetic energies of the two of them, the (c)________________ has the greater kinetic energy.
a. 12.9 b. 1.34 c. astronaut
A shopper pushes a 30 kg cart over 1.2 meters, pushing w/ a force of 12 Newtons. The work that the shopper does is (a)_____ joules, and if the shopping cart rolls frictionlessly, its speed is (b)______ m/s at the end of the push
a. 14.4 b. 0.97
"Mach" is a unit of speed which relates to the speed of sound. "Mach 1" is equal to the speed of sound in air. Aircrafts traveling above Mach 1 are called "supersonic", and aircrafts traveling much faster than Mach 1 are called "hypersonic." If a hypersonic aircraft is moving at Mach 7, give how fast it is moving: (a) in SI units and (b) in mph.
a. 2408 m/s b. 5327 mph
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? a. 5 m/s b. additional info is required c. 10 m/s d. 500 m/s
a. 5 m/s
Choose the physical principle listed below which is most closely related to Bernoulli's Principle a. Conservation of Energy b. Newton's Second Law c. Conservation of Momentum d. Newton's Third Law
a. Conservation of Energy
Choose all correct mathematical relationships below: a. Fnet=Δp/Δt b. p=1/2Fx^2 c. Favg = Δp/Δx d. Δp=Fnet⋅Δx e. Δp=Fnet⋅Δt
a. Fnet=Δp/Δt e. Δp=Fnet⋅Δt
which of the following correctly defines or describes "natural frequency"? a. natural frequency is an indicator of how often simple harmonic oscillators occur in nature b. natural frequency is the frequency at which a simple harmonic oscillator most naturally resists motion c. natural frequency is the frequency at which a driven simple harmonic oscillator resonates d. natural frequency is the frequency with which a simple harmonic oscillator must be pushed to keep in oscillating
c. natural frequency is the frequency at which a driven simple harmonic oscillator resonates
Consider each situation described below. In which situation is the angular momentum of the specified system not conserved? a. formation of a solar system--star and planets--from interstellar gas (system: solar system) b. figure skater performing a double-axel jump folding in their arms to increase their rotation speed (system: figure skater) c. precession of a bicycle wheel spinning vertically at a constant speed (system: bicycle wheel) d. a comet's orbit around the Sun (system: comet)
c. precession of a bicycle wheel spinning vertically at a constant speed (system: bicycle wheel)
Object 1 is given an initial velocity, while object 2 is at rest. If the 2 objects collide and stick together, what will happen after collision? a. they will move in the same direction as object 1's initial velocity but faster b. they will move opposite to the direction of object 1's initial velocity c. they will move in the same direction as object 1's initial velocity but slower
c. they will move in the same direction as object 1's initial velocity but slower
Which of the following objects have the smallest rotational inertia? Assume all objects have the same mass M. Each object is being rotated around an axis going through their center of mass, with this axis chosen to maximize the rotational inertia around the center of mass. a. thin, circular loop of radius R b. solid uniform sphere of radius R c. thin rod of length 2R d. spherical shell of radius R
c. thin rod of length 2R
Choose the statement below which most correctly describes when total momentum of objects in a system is conserved a. total momentum is conserved when only conservative forces act on objects in the system b. total momentum is conserved when no force acts on any objects in the system c. total momentum is conserved when the impulse due to net external force is equal to zero d. total momentum is conserved when no net work has been done
c. total momentum is conserved when the impulse due to net external force is equal to zero
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 a. 3×10^8 m/s b. 3,000 m/s c. 30,000 m/s d. 30 m/s e. 300 m/s
e. 300 m/s
thin, circular loop of radius R
largest rotational inertia
Solids
retains its own shape and size
spherical shell of radius R
second largest rotational inertia
thin rod of length 2R
smallest rotational inertia
solid uniform sphere of radius R
third largest rotational inertia
Just as Newton's Three Laws apply to linear motion, they (or rather, their analogous versions) also apply to rotational motion. Which of the following statements most correctly attributes a phenomenon of rotational motion to one of Newton's Three Laws of Motion? a. For every torque applied by Object A on Object B, there is a torque of equal magnitude and opposite direction applied by Object B on Object A, because of Newton's Third Law. b. Angular velocity of an object is proportional to the net torque on the object, because of Newton's Second Law. c. Angular acceleration of an object is proportional to net torque and inversely proportional to rotational inertia, because of Newton's Third Law. d. A constant net torque on an object will cause the object to rotate at a constant angular velocity, because of Newton's First Law.
a. For every torque applied by Object A on Object B, there is a torque of equal magnitude and opposite direction applied by Object B on Object A, because of Newton's Third Law.
Choose all statements below which correctly define or describe nodes and antinodes a. The antinodes are locations on a standing wave which exhibit the maximum displacement over the cycle of the wave. b. The positions of nodes and antinodes are swapped over one cycle of a standing wave, returning to their original positions on the next cycle. c. The nodes are the endpoints of a standing wave which is being excited at a specific frequency. d. The positions of nodes and antinodes do not change over the cycle of the wave. e. The nodes are locations on a standing wave which exhibit zero disturbance over time. f. The nodes and antinodes annihilate each other when they meet each other as they travel along the standing wave.
a. The antinodes are locations on a standing wave which exhibit the maximum displacement over the cycle of the wave. f. The nodes and antinodes annihilate each other when they meet each other as they travel along the standing wave.
Choose all situations below in which no work is done a. a cart slides along the floor frictionlessly b. a jogger runs up stairs at a constant speed c. a child pushes against a wall d. a teenager pushes a lawnmower across the lawn at a constant speed e. a weightlifter raises weights from the ground to overhead position f. a weightlifter holds weights in overhead position
a. a cart slides along the floor frictionlessly c. a child pushes against a wall f. a weightlifter holds weights in overhead position
Choose all situations below in which no work is done. a. a child holds dearly onto a spinning merry-go-round in order not to fall b. a traveler carries a suitcase on a level ground c. a parent catches a child's cart to slow it down to a stop d. backpackers hike up a gentle hill carrying 40 lb backpacks e. a weightlifter walks over a few meters horizontally carrying weights f. an athlete jumps up for a jumping rope exercise
a. a child holds dearly onto a spinning merry-go-round in order not to fall b. a traveler carries a suitcase on a level ground e. a weightlifter walks over a few meters horizontally carrying weights
The density of water is commonly expressed in 2 different units, either in g/cm^3 or in the basic SI units, kg/m^3. Choose the statement below which correctly gives the density of water in both units a. density of water is 1 g/cm^3, which is equal to 1,000 kg/m^3 b. density of water is 1,000 g/cm^3, which is equal to 1,000 kg/m^3 c. density of water is 1 g/cm^3, which is equal to 0.001 kg/m^3 d. density of water is 0.001 g/cm^3, which is equal to 1 kg/m^3
a. density of water is 1 g/cm^3, which is equal to 1,000 kg/m^3
Choose all units below which are correct units of power. a. kilogram meter^2/second^3 b. newton meter c. kilogram meter^2/second d. joule e. watt f. joule/second
a. kilogram meter^2/second^3 e. watt f. joule/second
Choose the unit below which is NOT a correct unit of work a. kilogram/second^2 b. newton meter c. kilogram meter^2/second^2 d. joule
a. kilogram/second^2
A delivery driver lifts a package of mass 5 kg by a height of 0.7 m to load it into a truck. Answer below questions. Use approximate value of gravitational acceleration g≈10 m/s^ 2 in this question. As the delivery driver lifts the package, how much work does gravitational force do? The gravitational force does (a)_________ work in the amount of (b)_____ joules
a. negative b. 35
Choose all statements below which correctly describe properties of a sound wave. a. sound wave in air is a longitudinal wave of compression and rarefaction of air molecules b. sound wave is propagation of mechanical vibration of molecules (in solid, liquid, or gas phase) through space c. sound wave is a mechanical movement of molecules through the air, propagating from the source of the wave d. higher frequency sound waves travel faster and farther than lower frequency sound waves e. the transverse component of sound wave in air travels slower than the longitudinal component of sound wave in air
a. sound wave in air is a longitudinal wave of compression and rarefaction of air molecules b. sound wave is propagation of mechanical vibration of molecules (in solid, liquid, or gas phase) through space
Consider the kinetic energies of a 20000kg truck moving at 36 m/s and a 50kg astronaut moving in orbit at 6200 m/s. Which of the two has greater kinetic energy? a. the astronaut b. the truck c. more info is needed d. neither
a. the astronaut
Study of olympic boxers show that punch of a boxer can deliver an impulse in the range of 550 kilogram·meter/second. If the contact of the punch lasts 0.11 second, estimate the average force of a boxer's punch. a. the average force of a boxer's punch is 5000 newtons b. the average force of a boxer's punch is 2000 newtons c. the average force of a boxer's punch is 6000 newtons d. the average force of a boxer's punch is 3000 newtons e. the average force of a boxer's punch is 4000 newtons
a. the average force of a boxer's punch is 5000 newtons
A weightlifter lifts a weight a height of 0.7m directly upward very slowly. If the weight weighs 200 N, how much work is done by the weightlifter? a. the weightlifter does 140 J of work b. the weightlifter does -140 J of work c. the weightlifter does 0 J of work d. the weightlifter does -1,400 J of work
a. the weightlifter does 140 J of work
Object 1 is given an initial velocity, while object 2 is at rest. If the 2 objects have the same mass and undergo an elastic collision, what will happen after collision? a. they will move in the same direction as object 1's initial velocity but slower b. object 1 will end up at rest and object 2 will move with the velocity object 1 initially had c. they will bounce off each other, and start moving in the direction opposite to their respective initial velocities d. they will end up at rest
b. object 1 will end up at rest and object 2 will move with the velocity object 1 initially had
Consider a situation below. Two objects of mass m=1 kg are on a level, frictionless surface. The first mass is moving towards the second mass (sitting at rest) at speed v=5 m/s. When the two masses collide, they stick to each other and move together as one piece. In this "totally inelastic collision," some kinetic energy is still left after the collision. Choose the statement below correctly explaining why, in this case, it is not be possible for the total kinetic energy to go to zero. a. to conserve momentum, the final momentum and velocity cannot be zero b. it is not possible in general to convert all kinetic energy to other forms of energy; there is always some waste kinetic energy c. there must be some potential energy (gravitational or elastic) for energy to go to, in order to have 0 kinetic energy d. it is not possible to have 0 kinetic energy on a frictionless surface
a. to conserve momentum, the final momentum and velocity cannot be 0
Choose all expressions which correctly relate different quantities involved in wave propagation. a. v=λ/T b. v=f/λ c. v=fλ d. T=λv e. λ=v/T f. f=v/λ g. T=λ/v h. λ=vT i. v=λT j. f=vλ
a. v=λ/T c. v=fλ f. f=v/λ h. λ=vT
Choose the statement below which correctly describes the relationship between wave speed, wave frequency, and wavelength. a. wavelength is given by wave velocity divided by wave frequency b. wave frequency is proportional to the wavelength of a wave c. wave frequency is given by the product of wave velocity and wavelength d. wavelength is given by the product of wave velocity and wave frequency
a. wavelength is given by wave velocity divided by wave frequency
Choose the correct description of the rotational phenomenon known as "precession" below a. "precession" refers to the necessity to spin up the main lifting blades of a helicopter before the lift-off b. "precession" refers to the change in orientation of a spinning object when an external torque acts on the object c. "precession" refers to the orientational stability of objects thrown or launched with a spin d. "Precession" refers to the tilt in the Earth's axis of spin with respect to its orbital plane
b. "Precession" refers to the change in orientation of a spinning object when an external torque acts on the object
Choose the statement below which correctly distinguishes between nodes and antinodes a. the nodes must be at the endpoints of the standing wave, while the antinode must be at the midpoint of the standing wave b. Destructive interference occurs at the locations of the nodes, while constructive interference occurs at the locations of the antinodes. c. the locations of the nodes do not move, but the locations of the antinodes move d. it is possible to have a standing wave with just nodes, while it is not possible to have a standing wave w/ just antinodes
b. Destructive interference occurs at the locations of the nodes, while constructive interference occurs at the locations of the antinodes.
Each of the statements below describes a property of a substance that applies to one or more states of matter. Choose the most accurate statement below. a. taking on the size of the container is a characteristic of liquids and gases only b. being able to carry a sound wave is a characteristic of all solids, liquids, and gases c. taking on the shape of the container is a characteristic of liquids only d. being included as "fluids" is a characteristic of solids and liquids only
b. being able to carry a sound wave is a characteristic of all solids, liquids, and gases
Which of the following does NOT describe a system that can undergo simple harmonic oscillator motion? a. mass on a pendulum b. cart on an inclined ramp c. mass hanging vertically from a spring d. marble in a bowl
b. cart on an inclined ramp
Choose the statement below which correctly defines or describes rotational inertia a. 2 objects with the same mass and the same center of mass will always have the same rotational inertia b. given the same mass, rotational inertia of larger--more spatially extended--objects are larger c. rotational inertia is a measure of how quickly an object comes to rest after being spun d. rotational inertia of a sphere is the same as the rotational inertia of a point mass at the center of the sphere, provided that they have the same mass
b. given the same mass, rotational inertia of larger--more spatially extended--objects are larger
Choose all statements below which correctly describe relationships between impulse and other physical quantities. a. impulse is a change in kinetic energy b. impulse is force times the duration of the force c. impulse is a sudden push or pull d. impulse is the magnitude of applied force e. impulse is the change of momentum
b. impulse is force times the duration of the force e. impulse is the change of momentum
Choose all units or combinations of units below which are correct units for momentum a. meter/second b. kilogram x meter/second c. newton d. pascal e. kilogram x meter/second^2 f. newton x second
b. kilogram x meter/second f. newton x second
Choose all statements below which correctly compare/contrast momentum w/ kinetic energy a. when kinetic energy does not change, momentum also does not change b. kinetic energy is a scalar, and momentum is a vector c. when speed of an object doubles, its kinetic energy quadruples and the magnitude of its momentum doubles d. when kinetic energy is zero, momentum is also zero e. when speed of an object doubles, both its kinetic energy and magnitude of its momentum doubles
b. kinetic energy is a scalar, and momentum is a vector d. when speed of an object doubles, its kinetic energy quadruples and the magnitude of its momentum doubles e. when kinetic energy is 0, momentum is also 0
Choose all statements below which correctly define or describe momentum a. momentum is the quantity of motion, mass times speed b. momentum is the quantity of motion, mass times velocity c. momentum of an object is constant, when the mass of the object remains the same d. momentum of an object is constant, when no net force acts on the object e. 2 objects w/ the same kinetic energy have the same momentum
b. momentum is the quantity of motion, mass times velocity d. momentum of an object is constant, when no net force acts on the object
Choose the statement below which correctly describes properties of a sound wave a. higher frequency sound waves travel faster and farther than lower frequency sound waves b. sound wave is propagation of mechanical vibration of molecules (in solid, liquid, or gas phase) through space c. the transverse component of sound wave in air travels slower than the longitudinal component of sound wave in air d. sound wave is a mechanical movement of molecules through the air, propagating from the source of the wave
b. sound wave is propagation of mechanical vibration of molecules (in solid, liquid, or gas phase) through space
Which of the following is not a constituent of mechanical energy? a. elastic potential energy b. thermal energy c. kinetic energy d. gravitational potential energy
b. thermal energy
Object 1 and 2 have the same mass and initially moving toward each other, w/ the same initial speed. If the 2 objects undergo an elastic collision, what will happen after collision? a. they will end up at rest b. they will bounce off each other, and start moving in the direction opposite to their respective initial velocities c. object 1 will end up at rest and object 2 will move with the velocity object 1 initially had d. they will move in the same direction as object 1's initial velocity but slower
b. they will bounce off each other, and start moving in the direction opposite to their respective initial velocities
Object 1 and 2 have the same mass and initially move toward each other, with the same initial speed. If the 2 objects collide and stick together, what will happen after collision? a. they will move in the same direction as object 1's initial velocity but slower b. they will end up at rest c. they will move in the same direction as object 2's initial velocity but slower d. they will bounce off each other, and start moving in the direction opposite to their respective initial velocities
b. they will end up at rest
Choose the statement below which correctly defines or describes "wavelength". a. wavelength is proportional to the frequency of the wave b. wavelength is the length of the smallest portion of the wave that repeats c. wavelength is inversely proportional to the amplitude of the wave d. wavelength is the length of spatial extent of the wave
b. 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. a. wavelength of a wave is like the amplitude of an oscillation b. wavelength of a wave is like the period of an oscillator c. wavelength of a wave is like the energy carried by the wave d. wavelength of a wave is like the frequency of an oscillator
b. wavelength of a wave is like the period of an oscillator
In each of the situations below, 2+ forces act on the object described. Net work is defines as the total work done by all the forces acting on the object. Choose all situations in which no net work is done. a. a toyota accelerates from 0-60 mph in 10 seconds b. a marathoner maintains a speed of 6 m/s in a race c. a textbook is raised very slowly from ground to the table d. a lawnmower is pushed across the lawn at a constant speed e. a cart slides down a frictionless ramp f. a shopping cart is accelerated from rest to 3 m/s
b/ a marathoner maintains a speed of 6 m/s in a race c. a textbook is raised very slowly from ground to the table d. a lawnmower is pushed across the lawn at a constant speed
Human hearing is sensitive to a small range of frequencies ("audible range"). Vibrations above or below this range are not audible to us. Choose the statement below which gives the audible range most accurately. a. 200-20,000 Hz b. 10-1,000 Hz c. 20-20,000 Hz d. 100-10,000 Hz
c. 20-20,000 Hz
Choose the statement below which correctly distinguishes between a transverse wave and a longitudinal wave a. In a transverse wave, the wave velocity is independent of the amplitude of the oscillation of the wave, but in a longitudinal wave, a component of the wave velocity is due to the amplitude, making larger-amplitude waves move faster. b. A transverse wave transports no material along the direction of wave propagation, while a longitudinal wave transports material along the direction of wave propagation. c. 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. d. A transverse wave travels in the horizontal direction, while a longitudinal wave travels in the vertical direction.
c. 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.
Helicopters have a small propeller on their tail to keep them from rotating in the opposite direction of their main lifting blades, as shown in the figure below. Which of Newton's Laws explain why the helicopter body will tend to rotate in the opposite direction to the blades? a. Newton's 2nd Law b. Newton's 1st Law c. Newton's 3rd Law d. Conservation of Energy
c. Newton's 3rd Law
Choose the correct statement below regarding amplitude, frequency, and period of a simple harmonic oscillator motion a. a simple harmonic oscillator oscillating w/ larger amplitude oscillates at a smaller frequency b. a simple harmonic oscillator oscillating with larger amplitude oscillates at a higher frequency c. a given simple harmonic oscillator oscillates at a fixed frequency, regardless of the amplitude of its motion d. the period of a simple harmonic oscillator is proportional to its frequency
c. a given simple harmonic oscillator oscillates at a fixed frequency, regardless of the amplitude of its motion
Choose the statement below which correctly defines or describes density a. density is used to relate the hardness of a substance to its volume b. density is related to the opacity of a given substance c. density is amount of mass in a given substance divided by the volume occupied d. density of an object increases when more of the same substance is present, increasing its mass
c. density is amount of mass in a given substance divided by the volume occupied
Which of the following most correctly describes the relationship between force and momentum? a. the net force points in the direction of momentum b. momentum is what causes forces c. force is the rate of change of momentum d. momentum is the net force
c. force is the rate of change of momentum
Choose all units below which are correct units of work. a. newton b. newton/meter c. kilogram meter^2/second^2 d. watt e. kilogram/second^2 f. joule
c. kilogram meter^2/second^2 f. joule
Choose all statements below which correctly defines or describes "wave velocity" or "wave speed" a. wave velocity is the speed at which masses that make up the wave move b. wave velocity is larger for larger-amplitude waves and smaller for smaller-amplitude waves c. wave velocity is a property of the medium and is independent of wave frequency or wavelength d. wave velocity is faster for higher-frequency waves and slower for lower-frequency waves e. wave velocity is the speed at which a disturbance travels through a medium
c. wave velocity is a property of the medium and is independent of wave frequency or wavelength e. wave velocity is the speed at which a disturbance travels through a medium
Choose the statement below which correctly defines or describes torque a. a given amount force can produce only a fixed amount of torque b. torque describes the degree to which a given material has been twisted c. with a greater lever arm, a given force can produce a greater torque d. torque is necessary to maintain an angular velocity
c. with a greater lever arm, a given force can produce a greater torque
Choose all statements below which correctly define or describe torque a. a given amount force can produce only a fixed amount of torque b. torque describes the degree to which a given material has been twisted c. with a greater lever arm, a given force can produce a greater torque d. torque is necessary to maintain an angular velocity e. torque is necessary to cause an angular acceleration
c. with a greater lever arm, a given form can produce a greater torque e. torque is necessary to cause an angular acceleration
A delivery driver lifts a package of mass 5 kg by a height of 0.7 m to load it into a truck. Answer below questions. Use approximate value of gravitational acceleration g≈10 m/s^ 2 in this question. Where did this increase in gravitational potential energy come from? a. fossil fuel b. mass of the package c. work done by the driver d. Earth
c. work done by the driver
solids, liquids, and gases
can carry a sound wave
Suppose on a stormy night, you see a lightning flash then hear the sounds of thunder about 7 seconds later. How far away do you estimate that the lightning struck? a. 0.3 km away b. 1.7 km away c. 2.0 km away d. 2.4 km away e. 0.7 km away
d. 2.4 km away
Choose the correct statement below regarding amplitude, frequency, and period of a simple harmonic oscillator motion a. the period of a simple harmonic oscillator is proportional to its frequency b. a simple harmonic oscillator oscillating with larger amplitude oscillates at a smaller frequency c. a simple harmonic oscillator oscillating with larger amplitude oscillates at a higher frequency d. a given simple harmonic oscillator oscillates at a fixed frequency, regardless of the amplitude of its motion
d. a simple harmonic oscillator oscillates at a fixed frequency, regardless of the amplitude of its motion
In which situation below is no work done? Choose the most correct answer. a. a teenager pushes a lawnmower across the lawn at a constant speed b. a jogger runs up stairs at a constant speed c. a weightlifter raises weights from the ground to overhead position d. a weightlifter holds weights in overhead position
d. a weightlifter holds weights in overhead position
Total momentum of a system experiencing net zero external force is conserved. Choose the statement below which is most correct and most relevant at explaining this. a. the velocity of a system experiencing net zero external force is also zero, so its momentum is conserved--at the numerical value of 0 b. according to Newton's Law of Universal Gravitation, a system not under a gravitational force doesn't experience an acceleration and therefore maintains its momentum c. according to Newton's First Law, the inertia of an object is conserved unless acted on by an external force d. according to Newton's 3rd Law, the momentum changes produced by the action force and the reaction force between objects internal to the system cancel out
d. according to Newton's 3rd Law, the momentum changes produced by the action force and the reaction force between objects internal to the system cancel out
Choose the expression which correctly relates different quantities involved in wave propagation. a. T=λv b. v=λT c. v=f/λ d. f=v/λ
d. f=v/λ
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? a. kinetic energy increased by a factor of √2 b. kinetic energy doubled c. kinetic energy tripled d. kinetic energy quadrupled
d. kinetic energy quadrupled
Choose all statements below which correctly define or describe rotational inertia a. Rotational inertia of a sphere is the same as the rotational inertia of a point mass at the center of the sphere, provided that they have the same mass. b. Two objects with the same mass and the same center of mass will always have the same rotational inertia. c. Rotational inertia is a measure of how quickly an object comes to rest after being spun. d. rotational inertia is a measure of how much an object resists angular acceleration e. given the same mass, rotational inertia of larger--more spatially extended--objects are larger
d. rotational inertia is a measure of how much an object resists angular acceleration e. given the same mass, rotational inertia of larger--more spatially extended--objects are larger
Recoil is a backward "kick" experienced in launching projectiles (or firing firearms, a special case of projectile). Suppose that the mass of the bullet for a pistol is 9 grams, and when fired, the bullet exits the pistol muzzle with a velocity of 390 m/s. If the mass of the pistol is 800 grams, what is the would-be recoil velocity of the pistol, if it is free to move backward? a. the recoil velocity of the pistol is 5.0 m/s b. the recoil velocity of the pistol is 5.9 m/s c. the recoil velocity of the pistol is 8.8 m/s d. the recoil velocity of the pistol is 4.4 m/s e. the recoil velocity of the pistol is 7.0 m/s
d. the recoil velocity of the pistol is 4.4 m/s
Choose the statement below which correctly defines or describes "wavelength" a. wavelength is proportional to the frequency of the wave b. wavelength is the length of spatial extent of the wave c. wavelength is inversely proportional to the amplitude of the wave d. wavelength is the length of the smallest portion of the wave that repears
d. wavelength is the length of the smallest portion of the wave that repeats
