PHYSICS EXAM MCQ PRACTICE

A meter stick balances at the 50.0-cm mark. If a mass of 50.0 g is placed at the 90.0-cm mark, the stick balances at the 61.3-cm mark. What is the mass of the meterstick? A. 127 g B. 178 g C. 89.7 g D. 32.6 g E. 73.4 g

A. 127 g

A net force of 200 N acts on a 100-kg boulder, and a force of the same magnitude acts on a 130-g pebble. How does the rate of change of the boulder's momentum compare to the rate of change of the pebble's momentum? A. greater than B. less than C. equal to

C. equal to

The momentum of an isolated system is conserved A. only in inelastic collisions. B. only in elastic collisions. C. in both elastic and inelastic collisions.

C. in both elastic and inelastic collisions.

You drive 6.0 km at 50 km/h and then another 6.0 km at 90 km/h. Your average speed over the 12 km drive will be A. greater than 70 km/h. B. equal to 70 km/h. C. less than 70 km/h. D. exactly 38 km/h. E. It cannot be determined from the information given because we must also knowdirections traveled.

C. less than 70 km/h.

A ball is thrown horizontally from the top of a tower at the same instant that a stone is dropped vertically. Which object is traveling faster when it hits the level ground below if neither of them experiences any air resistance? A. It is impossible to tell because we do not know their masses. B. the stone C. the ball D. Both are traveling at the same speed.

C. the ball

You push on box G that is next to box H, causing both boxes to slide along the floor,as shown in the figure. The reaction force to your push is A. the push of box G on box H. B. the push of box H on box G. C. the push of box G against you. D. the upward force of the floor n box G. E. the acceleration of box G.

C. the push of box G against you.

A tiger is running in a straight line. If we double both the mass and speed of the tiger, the magnitude of its momentum will increase by what factor? A. 2 B. 3 C. 1/2 D. 4

D. 4

A 60kg woman stands on the very end of a uniform board, of length l, which is supported one-quarter of the way from one end and is balanced. What is the mass of the board? A. 15kg B. 20kg C. 30kg D. 60kg E. 120kg

D. 60kg

Person X pushes twice as hard against a stationary brick wall as person Y. Which one of the following statements is correct? A. Both do positive work, but person X does four times the work of person Y. B. Both do positive work, but person X does twice the work of person Y. C. Both do the same amount of positive work. D. Both do zero work. E. Both do positive work, but person X does one-half the work of person Y.

D. Both do zero work.

When you apply the torque equation summation of torque = 0 to an object in equilibrium, the axis about which torques are calculated A. At the end B. At the COM C. At the pivot D. Can be located anywhere

D. Can be located anywhere

As you are leaving a building, the door opens outward. If the hinges on the door are on your right, what is the direction of the angular velocity of the door as you open it? A. Forwards B. Right C. Left D. Down E. Up

D. Down

A car speedometer reads the angular velocity of the tires. If a larger diameter tire is used instead, how will this affect the speedometer reading? A. It will read high B. It will always read 0 C. It will read the same D. It will read low

D. It will read low

Consider a uniform solid sphere of radius R and mass M rolling without slipping. Which form of its kinetic energy is larger, translational or rotational? A. Both forms of energy are equal B. You need to know the speed of the spher to tell C. Its rotational kinetic energy i larger than its translational kinetic energy D. Its translational kinetic energy is larger than its rotational kinetic energy

D. Its translational kinetic energy is larger than its rotational kinetic energy

A ball (mass 0.4 kg) is initially moving to the left at 30 m/s. After hitting the wall, the ball is moving to the right at 20 m/s. What is the impulse of the net force on the ball during its collision with the wall? A. 20 kg m/s to the right B. 20 kg m/s to the left C. 4 kg m/s to the right D. 4 kg m/s to the left

A. 20 kg m/s to the right

Calculation of the moment of inertia I for a uniform thin rod about an axis through the center of the rod. A. ML^2/12 B. M^2L/12 C. ML^2/6 D. ML^6/6 E. L^2/12 F. ML/2

A. ML^2/12

Calculation of the moment of inertia I for a uniform disk about an axis through center. A. MR^2/2 B. MR^2 C. MR^2/4 D. R^2/2 E. MR F. MR/2

A. MR^2/2

Which of the following quantities are units of impulse? A. N x s B. N x m C. J D kg x m/s

A. N x s

A system of particles is known to have a total momentum of zero. Does it necessarily follow that the total kinetic energy of the system i also zero? A. No B. Yes

A. No

Two forces produce the same torque. Does it follow that they have the same magnitude? A. No B. Yes C. it is not possible to tell

A. No

A person is sitting at rest on a stool that is free to rotate about a vertical axis. The person holds in one hand a bicycle wheel that spins rapidly counterclockwise (when viewed from above). The person then flips the wheel over. What happens as a result? A. The person rotates counterclockwise (as seen from above) B. The person rotates clockwise (as seens from above) C. Nothing. The wheel's angular momentum is simply dissipated in the person's body D. Nothing. The wheel's angular momentum remains the same before and after the flip E. The person flips over too

A. The person rotates counterclockwise (as seen from above)

A person is sitting at rest on a stool that is free to rotate about vertical axis. The person holds in one hand a bicycle wheel that spins rapidly counterclockwise (when viewed from above). The person then stops the wheel with the other hand. What happens as a result? A. The person rotates counterclockwise (as seen from above) B. The person rotates clockwise (as seen from above) C. Nothing. The wheel's angular momentum is carried away by external interactions D. Nothing. The wheel's angular momentum is simply dissipated by the friction interaction E. Something else happens

A. The person rotates counterclockwise (as seen from above)

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? A. The small car and the truck experience the same magnitude momentum change. B. The small car experiences the greater magnitude momentum change. C. The magnitude of the momentum change experienced by each one is directly proportional to its mass. D. The truck experiences the greater magnitude momentum change.

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

Consider a solid uniform sphere of radius R and mass M rolling without slipping. Which form of its kinetic energy is larger, translational or rotational? A. Translational kinetic energy is larger. B. Rotational kinetic energy is larger. C. Both are equal. D. You need to know the speed of the sphere to tell.

A. Translational kinetic energy is larger.

If the sum of both the external torques and the external forces on an object is zero,then the object must be at rest. A. True B. False

A. True

In an inelastic collision involving an isolated system, the final total momentum is A. exactly the same as the initial momentum. B. more than the initial momentum. C. less than the initial momentum.

A. exactly the same as the initial momentum.

An elevator suspended by a vertical cable is moving downward but slowing down. The tension in the cable must be A. greater than the weight of the elevator. B. less than than the weight of the elevator. C. equal to the weight of the elevator.

A. greater than the weight of the elevator.

When computing arc length, what unit must the angle be in? A. radians B. degrees C. meters D. seconds

A. radians

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. Bothforces are applied perpendicular to the door. Which force has a greater magnitude? A. the first force (at the midpoint) B. the second force (at the doorknob) C. The two forces are equal.

A. the first force (at the midpoint)

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? A. the normal force from the road B. the friction force from the road C. gravity D. No force causes the car to do this because the car is traveling at constant speed andtherefore has no acceleration.

A. the normal force from the road

A 15-kg child is sitting on a playground teeter-totter, 1.5 m from the pivot. What is the magnitude of the minimum force, applied 0.30 m on the other side of the pivot that is needed to make the child lift off the ground? A. 75 N B. 740 N C. 23 N D. 44 N E. 66 N

B. 740 N

When a rigid body rotates about a fixed axis, all the points in the body have the same A. Tangential speed B. Angular acceleration C. Linear displacement D. Centripetal acceleration E. Tangential acceleration

B. Angular acceleration

You are standing on a skateboard, initially at rest. A friend throws a very heavy balltowards you. You have two choices about what to do with the ball: either catch the ballor 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? A. Catch the ball. B. Deflect the ball back. C. Your final speed on the skateboard will be the same regardless whether you catchthe ball or deflect the ball.

B. Deflect the ball back.

Which object has more rotational KE? (Assume masses are equal.) A. Disk B. Hoop

B. Hoop

The momentum of an isolated system is conserved... A. Only in elastic collisions. B. In both elastic and inelastic collisions. C. Never. D. Only in inelastic collisions.

B. In both elastic and inelastic collisions.

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? A. Jacques has a greater angular speed than Ahmed. B. Jacques and Ahmed have the same angular speed. C. Jacques has a smaller angular speed than Ahmed. D. Jacques and Ahmed have the same tangential speed.

B. Jacques and Ahmed have the same angular speed.

Two object are known to have the same momentum. Do these two objects necessarily have the same kinetic energy? A. Yes B. No

B. No

Suppose that the speedometer of a truck is set to read the linear speed of the truck but uses a device that actually measures the angular speed of the tires. If larger diameter tires are mounted on the truck instead, how will that affect the speedometer reading as compared to the true linear speed of the truck? A. Speedometer reads a higher speed than the true linear speed B. Speedometer reads a lower speed than the true linear speed C. Speedometer still reads the true linear speed.

B. Speedometer reads a lower speed than that true linear speed

When a ball is thrown straight up with no air resistance, the acceleration at its highestpoint A. is upward B. is downward C. is zero D. reverses from upward to downward E. reverses from downward to upward

B. is downward

A net force of 200 N acts on a 100 kg boulder, and a force of the same magnitude acts on a 130-g pebble. How does the rate of change of the boulder's velocity compare to the rate of change of the pebble's velocity? A. greater than B. less than C. equal to

B. less than

A system of particles is known to have a total kinetic energy of zero. What can you say about the total momentum of the system? A. momentum of the system is negative B. momentum of the system is zero C. momentum of the system is positive D. you cannot say anything about the momentum of the system.

B. momentum of the system is zero

For general projectile motion with no air resistance, the horizontal component of aprojectile's velocity A. remains zero. B. remains a non-zero constant. C. continuously increases. D. continuously decreases.

B. remains a non-zero constant.

A uniform disk, a uniform hoop, and a uniform solid sphere are released at the same time at the top of an inclined ramp. They all roll without slipping. In what order do they reach the bottom of the ramp? A. hoop, disk, sphere B. sphere, disk, hoop C. disk, hoop, sphere D. sphere, hoop, disk E. hoop, sphere, disk

B. sphere, disk, hoop

When a car goes around a circular curve on a horizontal road at constant speed,what force causes it to follow the circular path? A. the normal force from the road B. the friction force from the road C. gravity D. No force causes the car to do this because the car is traveling at constant speed and therefore has no acceleration.

B. the friction force from the road

Two objects, one of mass m and the other of mass 2m, are dropped from the top of a building. If there is no air resistance, when they hit the ground A. both will have the same kinetic energy. B. the heavier one will have twice the kinetic energy of the lighter one. C. the heavier one will have four times the kinetic energy of the lighter one. D. the heavier one will have half the kinetic energy of the lighter one. E. the heavier one will have one-fourth the kinetic energy of the lighter one.

B. the heavier one will have twice the kinetic energy of the lighter one.

What is the torque about the point P due to the force F? A. 𝐹 ⋅ 𝑦 B. 𝐹 ⋅ 𝑥 C. 𝐹 ⋅ sin 𝜃 D. 𝐹 ⋅ 𝑙 E. 𝐹 ⋅ cos 𝜃

B. 𝐹 ⋅ 𝑥

Objects A, B, and C all have the same mass, all have the same outer dimension, and are all uniform. Object A: Disk Object B: Hoop Object C: Cube Rank them in order of their moment of inertia about an axis through the center from largest to smallest.

BCA

A uniform 40-N board supports two children weighing 500 N and 350 N. If the support is at the center of the board and the 500-N child is 1.5 m from its center, how faris the 350-N child from the center? A. 1.1 m B. 1.5 m C. 2.1 m D. 2.7 m

C. 2.1 m

Two vectors, of magnitudes 20 mm and 50 mm, are added together. Which one of the following is a possible value for the magnitude of the resultant? A. 10 mm B. 20 mm C. 40 mm D. 80 mm

C. 40 mm

A 3kg rifle fires a 0.005kg bullet at a speed of 300 m/s. Which force is greater in magnitude: the force that the rifle exerts on the bullet or the force that the bullet exerts on the rifle? A. The force that the rile exerts on the bullet is greater. B. The force that the bullet exerts on the rifle is greater. C. Both forces have the same magnitude. D. The answer depends on how the rifle is held. E. The answer depends on how the rifle is held ad on the inner workings of the rifle.

C. Both forces have the same magnitude.

A satellite is in orbit around the earth. Which one feels the greater force? A. the satellite because the earth is so much more massive B. the earth because the satellite has so little mass C. Earth and the satellite feel exactly the same force. D. It depends on the distance of the satellite from Earth.

C. Earth and the satellite feel exactly the same force.

A heavy ball suspended by a cable is pulled to the side by a horizontal force F. IF angle theta is small the magnitude of the force F can be less than the weight of the ball because: A. the force holds up only part of the ball's weight B. even through the ball is stationary, it is not really in equilibrium C. F is equal to only the x component of the tension in the cable D. the original statement is not true. To move the ball. F must be at least equal to the ball's weight

C. F is equal to only the x component of the tension in the cable

Suppose that an object travels from one point in space to another. Make a comparison between the magnitude of the displacement and the distance traveled by this object. A. The displacement is either greater than or equal to the distance traveled. B. The displacement is always equal to the distance traveled. C. The displacement is either less than or equal to the distance traveled. D. The displacement can be either greater than, smaller than, or equal to the distancetraveled.

C. The displacement is either less than or equal to the distance traveled.

A 10N weight is suspended by two cords. What can you say about the tension in the two cords? (sorry I cannot post pictures I don't have premium) A. The tension in both cords is 5N B. The tension in both cords is equal but not 5N C. The tension in cord A is greater than that in cord B D. The tension in cord B is greater than that in cord A

C. The tension in cord A is greater than that in cord B

You throw a baseball straight up. Compare the sign of the work done by gravity while the ball goes up with the sign of the work done by gravity while it goes down. A. The work is positive on the way up and positive on the way down. B. The work is positive on the way up and negative on the way down. C. The work is negative on the way up and positive on the way down. D. The work is negative on the way up and on the way down because gravity is alwaysdownward.

C. The work is negative on the way up and positive on the way down.

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. The clay sticks to the wall. Which one of these objects experiences the greater momentum change? A. Both of them experience zero momentum change. B. Both of them experience the same non-zero momentum change. C. The clay. D. The ball.

D. The ball.

A truck going 15 km/h has a head-on collision with a small car going 30 km/h. Which statement best describes the situation? A. The truck has the greater change of momentum because it has the greater mass. B. The car has the greater change of momentum because it as the greater speed. C. Neither the car nor the truck changes its momentum because momentum is conserved. D. They both have the same change in magnitude of momentum because momentum is conserved.

D. They both have the same change in magnitude of momentum because momentum is conserved.

In the formula for torque, where does the moment arm (r→ ) point to / from? A. from the center of mass to the edge of the object B. from the force application point to the middle of the object C. from the force application point to the pivot D. from the pivot to the force application point E. from the pivot to the center of mass

D. from the pivot to the force application point

An object at rest begins to rotate with a constant angular acceleration. If this object rotates through an angle q in the time t, through what angle did it rotate in the time 1/2 t? A. 3q/4 B. 4q C. q/2 D. q/4 E. 2q

D. q/4

A DVD is initially at rest. It then begins to rotate counterclockwise with constant angular acceleration alpha. After the DVD has rotated through an angle theta its angular speed is w. If instead the DVD is initially at rest and its constant angular acceleration is double to 2alpha after the DVD has rotated through the same angle, its angular speed will be A. w/2 B. w/sqrt(2) C. w D. wsqrt(2) E. 2w

D. wsqrt(2)