physics

you drag your feet across the carpet and then touch a doorknob receving a small shock. How did the charge transfer between you and the door?

conduction

Mary and Debra stand on a snow-covered roof. They both throw snowballs with the same initial speed, but in different directions. Mary throws her snowball downward, at 30 degrees below the horiztonal; debra throws her snowball upward, at 30 degrees above the horizontal

debras snowball will stay in the air longer than mary's debra's has exactly same acceleration as mar's

you are standing on a skateboard, initially at rest. A friend throws a very heavy ball towards you. you have two choices about what to do with the ball: either catch the ball or deflect it back toward your friend with the same speed as it was originally thrown. Which choice should you make in order to maximize your speed on the skateboard?

deflect the ball

a bucket is being lowered by a very light rope with a constant downward velocity. The tension in the rope must be

equal to the weight of the bucket

A box is placed on a table which rests on the floor. The box pushes on the table; the reaction force to the box's push on the table is the table's push on the floor

false

if the rockets of a spaceship in outer space (far from all gravity) suddenly lose power and turn off, the spaceship will gradually slow to a stop

false

in order to get an object moving, you must push harder on it than it pushes back on you

false

Jill does twice as much work as Jack does and in half the time. Jill's power output is

four times jack's power output

an elevator suspended by a vertical cable is moving downward but slowing down. The tension in the cable must be

greater than the weight of the elevator

Hailey's comet is in a highly elliptical orbit around the sun. Therefore, the orbital speed of Halley's comet, while traveling around the sun

increases as it nears the sun

one heavily negatively charged object A is brought near to a neutral object B that is grounded. After some time, t, the ground is removed and the objects are separated. What process is being described and what is the charge on object B after the process has occurred?

induction; postive

for general projectile motion with no air resistance, the horizontal component of a projectile's acceleration

is always zero

A small car and a large SUV are at a stoplight. The car has a mass equal to half that of the SUV, and the SUV can produce a maximum accelerating force equal to twice that of the car. When the light turns green, both drivers push their accelerators to the floor at the same time. Which vehicle pulls ahead of the other vehicle after a few seconds

it is a tie

A solid sphere and a solid cylinder, both uniform and of the same mass and radius, roll without slipping at the same forward speed. It is correct to say that the total kinetic energy of the solid sphere is

less than the total kinetic energy of the cylinder

A crate is sliding down an inclined ramp at a constant speed of 0.55 m/s. The vector sum of all the forces acting on this crate must point

none of the above choices is correct

The figure above shows two wave pulses that are approaching each other. Which of the following best shows the shape of the resultant pulse when the center of the pulses, points P and Q, coincide?

one single small rectangle less than midway thru

What would be the weight of a 59.1 kg astronaunt on a planet twice as masive as Earth having twice earth's radius

one-half of its weight on the surgace of the earth

For general projectile motion with no air resistance, the horizontal component of a projectile's velocity during its flight

remains a non-zero constant

For general projectile motion with no air resistance, the vertical component of a projectile's acceleration

remains a non-zero constant

you are in a train traveling on a horizontal track and notice that a piece of luggage starts to slide directly toward the front of the train. From this observation, you can conclude that this train is

slowing dwon

a player kicks a soccer ball in a high arc toward the opponent's goal. At the highest point in its trajectory

the ball's vertical acceleration points downward

you have a raw egg and a cooked egg. If you exert the same torque on each of them for the same period of time, which one spins faster in the end?

the cooked egg

When unequal resistors are connected in series across an ideal battery,

the current flowing in each is the same

a heavy dart and a light dart are launched horizontally on a frictionless table by identical ideal springs. Both springs were initially compressed by the same amount. Which of the following statements about these darts are correct?

the darts both have the same kinetic energy just as they move free of the spring the lighter dart leaves the spring moving faster than the heavy dart both darts had the same initial elastic potential energy

Two forces produce equal torques on a door about the door hinge. The first force is applied at the midpoint of the door; the second force is applied at the doorknob. Both forces are applied perpendicular to the door. Which force has a great magnitude?

the first force (at the midpoint)

When a car goes around a circular curve on a horizontal road at constant speed, what force causes it to follow the circular path?

the friction force from the road

two objects of different mass have equal, non-zero kinetic energies. Which object has the greater magnitude momentum?

the heavier objecy

you drop a 50 g egg from a 5th story window where it land on the ground below. Will the following changes A increase B decrease C cause no change to the final velocity the egg has just before it hits the ground

the mass of the egg is doubled C the egg is thrown with an initial downward velocity A the egg is dropped from the 10th story A the egg is dropped on the moon B the egg is thrown with an initial upward velocity A

an object is moving the constant non-zero velocity. Which of the following statements about it must be true?

the net force on the object is zero

when a car goes around a banked circular curve at the proper speed for the banking angle, what force cause it to follow the circular path?

the normal force from the road

In each case below, a string is attached to one of more identical blocks. All of the masses are at rest. The strings are so light that they can be considered to be massless in cases A-E, the string pass over pulleys that are frictionless and massless. Rank these situations based on the tension

the tension is the same for all arrangements

in a collision between two unequal masses, which mass receives a greater magnitude impulse?

they receive equal impulses

Swimmers at a water park have a choice of two frictionless water slides, as shown in the figure. Although both slides drop over the same height h, slide 1 is straight while slide 2 is curved, dropping quickly at first and then leveling out. How does the speed v1 of a swimmer reaching the bottom of slide 1 compare with v2, the speed of a swimmer reaching the end of slide 2

v1 = v2

In the diagram to the right, at what point is the normal force the greatest?

A- the bottom one

identical light bulbs can be attached to identical batteries in three different ways (A, B, or C) as shown in the figure. The ranking (from lowest to highest) of the total power produced by the battery is)

B, A, C

Two small balls, A and B, attract each other gravitationally with a force of magnitude F. If we now double both masses and the separation of the balls, what will now be the magnitude of the attractive force on each one?

F

In the figure, determine the character of the collision. The mass of the blocks, and the velocities before and after, are shown. The collision is

elastic

A person who normally weighs 700 N is riding in an elevator that is moving upward but slowing down at a steady rate. If this person is standing on a bathroom scale inside the elevator, what would the scale read

less than 700N

Two boxes P and Q on a perfectly smooth horizontal surface are connected by a light horizontal cord. The mass of P is greater than that of Q. A horizontal force F is applied to box Q as shown in the figure, accelerating the bodies to the right. The magnitude of the force exerted by connecting cord on body P is

less than F but not zero

An object undergoing simple harmonic motion has an amplitude of 4m and an angular velocity of 3 rad s. Which equation below accurately represents the projected position of the object?

x = 4cos3t x = 4sin3t

a forklift pushes a 100kg crate, starting from rest, with a horizontal force of magnitude F. The graph in the figure shows the x component of this force as a function of time. What is the instantaneous velocity of the crate at time t = 10s?

-75 cm/s

The graph in the figure shows the x component F of the net force that acts for 10s on a 100kg crate. What is the change in the momentum of the crate during the 10s that this force acts?

-75 kg m/s

As shown in the figure below, a given force is applied to a rod in several different ways. In which case is the torque above the pivot due to this force the greatest?

1

A force produces power P by doing work W in a time T. What power will be produced by a force that does six times as much work in half as much time

12P

The figure shows a 100-kg block being released from rest from a height of 1.0 m. It then takes 0.53s for it to reach the floor. What is the mass m of the block on the left? There is no friction or mass in the pulley, and the connecting rope is very light

16 kg

Double the battery's voltage has the effect of changing the current through the 2 ohm resistor by what factor

2

In the circuit, which resistor has the greatest current flowing through it (write all that apply on line)

2, 5

the figure shows an object's acceleration versus force graph. What is the mass of this object

2.5g

when 1.0-uC point charge is 15m from a second point charge, the force each one experience a force of 1.0uN. What is the magnitude of the second charge?

25nC

When you drop a pebble from height H, it reaches the ground with kinetic energy K if there is no air resistance. From what height should you drop it so it will reach the ground with twice as much kinetic energy?

2H

Rank the above resistors by least voltage drop to greatest voltage drop

3, 6, 2, 4, 5

a force acts on an object, causing it to move parallel to the force. The graph in the figure shows this force as a function of the position of the object. How much work does the force do as the object moves from 6m to 12m

30J

Planet Z-34 has a mass equal to one-third that of Earth and a radius equal to one-third that of Earth. With g representing, as usual, the acceleration due to gravity at the surface of Earth, the acceleration due to gravity at the surface fo Z-34

3g

The position of a mass that is undergoing simple harmonic motion can be projected by the following equation Xmax = 16cospi/2t. What is the period of this object?

4.0s

A person who normally weighs 700 N is riding in a rather swift elevator that is moving at a constant speed of 9.8 m/s. If this person is standing on a bathroom scale inside the elevator, what would the scale read?

700N

Rank the orbital velocities of these 5 satellites that are currently geo-stationary around planet Xenon from least to greatest

A C D&F B&E

the figures below show six situations where the same block, which has a mass of 5 kg, remains at rest on either a horizontal or an inclined surface. the surfaces are all made of the same material. In all cases except case A, a 4N force acts on the block parallel to the surface as indicated by the arrow in the diagram. rank based on magnitude of frictional force

A D&F C B&E

two identical grasshoppers jump into the air with the same initial speed and experience no air resistance. Grasshopper A goes straight up, but Grasshopper B goes up at a 66 degree angle above the horizontal. Which of the following statements about these grasshoppers are correct

At their highest point, -both of them have the same amount of mechanical energy Grasshopper B is moving faster than A A has more gravitational potential energy than B

The figures show scale drawings of four objects, each of the same mass and uniform thickness with the mass distributed uniformly. Which one has the greatest moment of inertia when rotated about an axis perpendicular to the plane of the drawing at point P? Spheres A and C are solid.

B

You and your friend, who weighs the same as you, want to go to the top of the Eiffel Tower. Your friend takes the elevator straight up. You decide to walk up the spiral stairway, taking longer to do so. Compare the gravitational potential energy of you and your friend, after you both reach the top.

Both of you have the same amount of gravitational potential energy at the top.

Two uniform solid balls, one of radius R and mass M, the other of radius 2R and mass 8M, roll down a high incline. They start together from rest at the top of the incline. Which one will reach the bottom of the incline first?

Both reach the bottom at the same time

A small vibrating object on the surface of a ripple tank is the source of waves of frequency 20 Hz and speed 60 cm/s. If the source S is moving to the right, as shown above, with speed 20 cm/s, at which of the labeled points will the frequency measured by a stationary observer be greatest?

C

Two blocks, A and B, are being pulled to the right along a horizontal surface by a horizontal 100-N pull, as shown in the figure. Both of them are moving together at a constant velocity of 2.0 m/s to the right, and both weigh the same. Which of the figures below shows a correct FBD of the horizontal forces acting on the lower block,B

C 100n left, 100N right

Two blocks, A and B, are being pulled to the right along a horizontal surface by a horizontal 100-N pull, as shown in the figure. Both of them are moving together at a constant velocity of 2.0 m/s to the right, and both weigh the same. Which of the figures below shows a correct free-body diagram of the horizontal forces acting on the upper block, A?

C just block A with no horizontal forces acting on

Three cars (car L, car M, and car N) are moving with the same speed and slam on their brakes. The most massive car is car L and the least massive is car N. If the tires of all three cars have identical coefficients of kinetic friction with the road surface, for which car is the amount of work done by friction in stopping it the greatest?

Car L

Two objects of unequal masses, M and m (M > m) are connected by a very light cord passing over an ideal pulley of negligible mass as shown. When released, the system accelerates, and the friction is negligible. Which one of the following free-body diagrams most realistically represents the forces acting on the two objects in the moving system?

D M has an equal up arrow as m and m's down arrow is smaller

in the figure, what would the spring scale read? the pulleys are ideal, and the strings and scale are also massless

Exactly 1.0N

a block of mass m sits on a rough inclined ramp that makes an angle 60 degrees with the horizontal. What must be true about normal force F on the block due to the ramp

F = mg cos 60 f = mg sin 30

in a collision between a huge SUV and a small hybrid car, the SUV exerts a larger force on the hybrid

False

Five forces act of a rod that is free to pivot at point P, as shown in the figure below. Which of these forces is producing a counter-clockwise torque about point P

Force C

The following table is data from 4 lab groups each had different circuits. Which data best reflects the circuit shown?

Group B

In the doppler effect for sound waves, factors that affect the frequency that the observer hears include which of the following?

I the speed of the source

In the circuit shown in the figure, the resistor R has a variable resistance. As R is decreased, what happens to the currents?

I1 increases and I2 decreases

two point charges, Q1 and Q2, are separated by a distance R. If the magnitudes of both charges are doubled and their separation is halved, what happens to the electrical force that each charge exerts on the other one?

It increases by a factor of 16

A spaceship is traveling to the Moon. At what point is it beyond the pull of Earth's gravity?

It is never beyond the pull

Two children, Ahmed and Jacques, ride on a merry-go-round. Ahmed is at a greater distance from the axis of rotation than jacques. Which of the following are true statements?

Jacques and Ahmed have the same angular speed Ahmed has a greater tangential speed than Jacques.

a truck has four times the mass of a car and is moving with twice the speed of the car. If Kt and Kc refer to the kinetic energies of truck and car respectively, it is correct to say that

Kt = 16Kc

The acceleration due to gravity is lower on the moon than on earth. Which of the following statements is true about the mass and weight of an astronaut on the moon's surface, compared to Earth

Mass is the same, weight is less

A string fixed at both ends is vibrating in one of its harmonics. If we now increase the frequency at which the string is vibrating, which of the following characteristics do we also increase?

None of the above

An organ pipe of length L that is open at one end resonates in its third harmonic with a wavelength of 2L/3. Is the other end of the pipe closed or open?

Open

A push of magnitude P acts on a box of weight W as shown in the figure the push is directed at an angle O below the horizontal, and the box remains a rest. The box rests on a horizontal surface that has some friction with the box. The friction force on the box due to the floor is equal to

PcosO

Bill and his daughter Susan are both standing on identical skateboards (with really good frictionless ball bearings), initially at rest. Bill weighs three times as much as Susan. Bill pushes horizontally on Susan's back, causing Susan to start moving away from Bill. Just after Bill stops pushing,

Susan and Bill are moving away from each other, and Susan's speed is 3 times that of Bill

A satellite of mass M takes time T to orbit a planet. If the satellite had twice as much mass, the time for it to orbit the planet at the same altitude would be

T

inside of a train a ball of weight W is hanging by a light wire at rest from the ceiling. The wire makes an angle with the ceiling, as shown in the figure. Which one of the following conditions must be true about the tension T in the wire?

T sin o = W

a ball is attached to an ideal spring and oscillates with a period T. If the mass of the ball is doubled, what is the new period?

T*square root 2

Three boxes are pulled along a horizontal frictionless floor by a constant pull P. The boxes are connected by very light horizontal strings having tensions T1 and T2 as shown in the figure. Which of the following statements about the tensions is correct?

T1 > T2

Two cyclists who weigh the same and have identical bicycles ride up the same mountain, both starting at the same time. Joe rides straight up the mountain, and Bob rides up the longer road that has a lower grade. Joe gets to the top before Bob. Ignoring friction and wind resistance, which of the following statements is true?

The amount of work done by Joe is equal to the amount of work done by Bob, but the average power exerted by Joe is greater than that of Bob

A rubber ball and a lump of clay have equal mass. They are thrown with equal speed against a wall. The ball bounces back with nearly the same speed with which it hit. They clay sticks to the wall. Which one of these objects experiences the greater momentum change?

The ball

A 9-V battery is hooked up to two resistors in series using wires of negligible resistance as shown above. One has a resistance of 5 ohm, and the other has a resistance of 10 ohm. Several locations along the circuit are marked with letters, as shown in the figure. Which statements about this circuit are true?

The current is exactly the same at ABCD the potential at B is equal to that at C

Four unequal resistors are connected in a parallel with each other. Which one of the following statements is correct about this combination?

The equivalent resistance is less than that of the smallest resistor

Two equal magnitude forces are applied to a door at the doorknob. The first force is applied perpendicular to the door, and the second force is applied at 30 to the plane of the door. Which force exerts the greater torque about the door hinge?

The first force (applied perpendicular to the door)

Two tiny beads are 25 cm apart with no other charges or fields present. Bead A carries 10uC of charge and bead B carries 1uC. Which one of the following statements is true about the magnitudes of the electric forces on these beads?

The force on A is exactly equal to the force on B

A pendulum of length L is suspended from the ceiling of an elevator. When the elevator is at rest the period of the pendulum is T. How does the period of the pendulum change when the elevator moves upward with constant acceleration?

The period decreases

a small car meshes with a large truck in a head-on collision. Which of the following statements concerning the magnitude of the momentum change during the collision is correct?

The small car and the truck experience the same magnitude momentum change

Two objects have masses m and 5m respectively, they both are placed side by side on a frictionless inclined ramp and allowed to slide down from rest without any air resistance. Which of the following statements about these objects is correct?

The two objects reach the bottom of the ramp at exactly the same time

Consider a pipe of length L that is open at both ends is resonating at its fundamental frequency. Which statement about the sound is correct?

The wavelength is 2L and there is a displacement node at the pipe's midpoint

When a rigid object rotates about a fixed axis, what is true about all the points in the object?

They all have the same angular speed.

A pull of magnitude P acts on a box of weight W as shown in the figure. The pull is directed at an angle above the horizontal, and the box remains a rest. The box rests on a horizontal surface that has some friction with the box. The normal force on the box due ot the floor is equal to

W - P Sin O

a 75-N box rests on a perfectly smooth horizontal surface. The minimum force need to start the box moving is

any horizontal force greater than zero

a pilot drops a package from a plane flying horizontally at a constant speed. Neglecting air resistance, when the package hits the ground the horizontal location of the plane will

be directly over the package