PHYS 1150 Final

An object is moving forward with a constant velocity. Which statement about this object must be true? A) The net force on the object is zero. B) The net force on the object is in the forward direction. C) No forces are acting on the object. D) The acceleration of the object is in the forward direction.

A

Jan and Len throw identical rocks off a tall building at the same time. The ground near the building is flat. Jan throws her rock straight downward. Len throws his rock downward and outward such that the angle between the initial velocity of the rock and the horizon is 30°. Len throws the rock with a speed twice that of Jan's rock. If air resistance is negligible, which rock hits the ground first? A)They hit at the same time. B)Jan's rock hits first. D)Len's rock hits first. C)It is impossible to know from the information given.

A

When you ride a bicycle, in what direction is the angular velocity of the wheels? A) to your left B) to your right C) forwards D) backwards E) up

A

A baseball is thrown vertically upward and feels no air resistance. As it is rising A) both its momentum and its mechanical energy are conserved. B) its momentum is not conserved, but its mechanical energy is conserved. C) both its momentum and its kinetic energy are conserved. D)its kinetic energy is conserved, but its momentum is not conserved. E) its gravitational potential energy is not conserved, buts its momentum is conserved.

B

A uniform solid sphere has a moment of inertia I about an axis tangent to its surface. What is the moment of inertia of this sphere about an axis through its center? A) 1/7 I B) 2/7 I C) 2/5 I D) 3/5 I E) 7/5 I

B

Suppose that an object is moving with constant nonzero acceleration. Which of the following is an accurate statement concerning its motion? A)In equal times its speed changes by equal amounts. B)In equal times its velocity changes by equal amounts. C)In equal times it moves equal distances. D) A graph of its position as a function of time has a constant slope. E) A graph of its velocity as a function of time is a horizontal line.

B

The figure shows the velocity of a particle as it travels along the x-axis. What is the direction of the acceleration at t = 0.5 s? A) in the +x direction B) in the -x direction C) The acceleration is zero.

B

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)tangential acceleration. D) linear displacement. E) centripetal acceleration.

B

While an object is in projectile motion (with upward being positive) with no air resistance A) the horizontal component of its velocity remains constant and the horizontal component of its acceleration is equal to -g. B) the horizontal component of its velocity remains constant and the vertical component of its acceleration is equal to -g. C) the horizontal component of its velocity remains constant and the vertical component of its acceleration is equal to zero. D) the vertical component of both its velocity and its acceleration remains constant. E) the vertical component of its velocity remains constant and the vertical component of its acceleration is equal to -g.

B

A ball is thrown directly upward and experiences no air resistance. Which one of the following statements about its motion is correct? A) The acceleration of the ball is upward while it is traveling up and downward while it is traveling down. B) The acceleration of the ball is downward while it is traveling up and upward while it is traveling down. C) The acceleration is downward during the entire time the ball is in the air. D) The acceleration of the ball is downward while it is traveling up and downward while it is traveling down but is zero at the highest point when the ball stops.

C

A shell explodes into two fragments, one fragment 25 times heavier than the other. If any gas from the explosion has negligible mass, then A) the momentum change of the lighter fragment is 25 times as great as the momentum change of the heavier fragment. B) the momentum change of the heavier fragment is 25 times as great as the momentum change of the lighter fragment. C) the momentum change of the lighter fragment is exactly the same as the momentum change of the heavier fragment. D) the kinetic energy change of the heavier fragment is 25 times as great as the kinetic energy change of the lighter fragment. E) the kinetic energy change of the lighter fragment is 25 times as great as the kinetic energy change of the heavier fragment.

C

In a collision between two objects having unequal masses, how does magnitude of the impulse imparted to the lighter object by the heavier one compare with the magnitude of the impulse imparted to the heavier object by the lighter one? A) The lighter object receives a larger impulse. B) The heavier object receives a larger impulse. C) Both objects receive the same impulse. D) The answer depends on the ratio of the masses. E) The answer depends on the ratio of the speeds.

C

In an INELASTIC collision between two objects A) the momentum of each object is conserved. B) the kinetic energy of each object is conserved. C) the momentum of the system is conserved but the kinetic energy of the system is not conserved. D) both the momentum and the kinetic energy of the system are conserved. E) the kinetic energy of the system is conserved, but the momentum of the system is not conserved.

C

A uniform solid sphere of mass M and radius R rotates with an angular speed about an axis through its center. A uniform solid cylinder of mass M, radius R, and length 2R rotates through an axis running through the central axis of the cylinder. What must be the angular speed of the cylinder so it will have the same rotational kinetic energy as the sphere? A) 2/5 B) (Sqrt 2/5) w C) 4w/5 D) 2w/sqrt 5 E) w/sqrt 5

D

In a perfectly ELASTIC collision between two perfectly rigid objects A) the momentum of each object is conserved. B) the kinetic energy of each object is conserved. C) the momentum of the system is conserved but the kinetic energy of the system is not conserved. D) both the momentum and the kinetic energy of the system are conserved. E) the kinetic energy of the system is conserved, but the momentum of the system is not conserved.

D

Two objects have masses m and 5m, respectively. They both are placed side by side on a frictionless inclined plane and allowed to slide down from rest. A) It takes the lighter object 5 times longer to reach the bottom of the incline than the heavier object. B) It takes the lighter object 10 times longer to reach the bottom of the incline than the heavier object. C) It takes the heavier object 5 times longer to reach the bottom of the incline than the lighter object. D) It takes the heavier object 10 times longer to reach the bottom of the incline than the lighter object. E) The two objects reach the bottom of the incline at the same time.

E

Is it possible for a system to have negative potential energy? A) Yes, as long as the kinetic energy is positive. B) Yes, as long as the total energy is positive. C) Yes, since the choice of the zero of potential energy is arbitrary. D) No, because the kinetic energy of a system must equal its potential energy. E) No, because this would have no physical meaning

C

Two identical objects A and B fall from rest from different heights to the ground and feel no appreciable air resistance. If object B takes TWICE as long as object A to reach the ground, what is the ratio of the heights from which A and B fell? A) hA/hB = 1/sqrt 2 B) hA/hB = 1/2 C) hA/hB = 1/4 D) hA/hB = 1/8

C

Two objects are thrown from the top of a tall building and experience no appreciable air resistance. One is thrown up, and the other is thrown down, both with the same initial speed. What are their speeds when they hit the street? A) The one thrown up is traveling faster. B) The one thrown down is traveling faster. C) They are traveling at the same speed.

C

If the acceleration of an object is negative, the object must be slowing down. True False

False