Either
Two carts, A and B, collide on a horizontal air track without friction. Cart A has a mass of 2.0 kg and is moving at 3.0 m/s to the right, while cart B has a mass of 3.0 kg and is initially at rest. After the collision, cart A is at rest. The velocity of cart B after the collision?
A. 2.0 m/s to the left
B. 1.0 m/s to the left
C. 2.0 m/s to the right
D. 1.0 m/s to the right
E. 0 m/s
What is C? [2.0m/s to the right]
A brick, initially at rest, is dropped from the roof of a building. The brick falls for 2.8 seconds before hitting the ground. The height of the building?
A. 77 m
B. 51 m
C. 38 m
D. 27 m
E. 22 m
What is C? [38m]
Identify correct statements regarding adiabatic compression in an engine: (1)No heat exchange with surroundings, (2)Negative work done by gas, (3)Increase in internal energy of gas.
A. Only (1) is correct
B. Only (2) is correct
C. Only (3) is correct
D. Only (1) and (3) are correct
E. All (1)-(3) are correct
What is E? [All (1)-(3) are correct]
A circular saw blade 0.150 m in diameter undergoes constant angular acceleration, starting from rest, and reaches a cutting speed of 500 rad/s in 2.00 s. The angle does the blade turn through as it reaches the cutting speed?
A. 250 radians
B. 1500 radians
C. 500 radians
D. 750 radians
E. 1000 radians
What is C? [500 radians]
A spaceship moves at a constant speed of v = 100 m/s around a circular path in outer space. If the spaceship moves in a vertical circle with a radius of R = 400 m, what is the magnitude of its total acceleration (a) at its lowest point of the circle?
A. 25.0 m/s2
B. 10.0 m/s2
C. 50.0 m/s2
D. 100 m/s2
E. 125 m/s2
What is A? [25.0m/s2]
A bullet is shot straight up with an initial speed of 150m/s. Identify correct statements about the bullet's motion at its highest point: (1) The speed of the bullet is zero, (2) The acceleration of the bullet is zero, (3) The magnitude of the acceleration of the bullet is 9.81m/s2.
A. Only (1) is correct
B. Only (2) is correct
C. Only (3) is correct
D. Only (1) and (2) are correct
E. Only (1) and (3) are correct
What is E? [Only (1) and (3) are correct]
Two point-like ladybugs, each with equal mass, sit on a disk that rotates about the z-axis, as shown in the figure. The ladybugs are at rest with respect to the disk's surface and do not slip. Ladybug 1 is halfway between ladybug 2 and the axis of rotation. Let Li and L2 be the respective magnitudes of their angular momenta for their rotations about the disk's center. Identify the following correct statement.
A. L1 = L2, and they point in the +z direction
B. L1 = L2, and they point in the -z direction
C. L1 < L2, and they point in the +z direction
D. L1 < L2, and they point in the +y direction
E. L1 < L2, and they point in the -z direction
What is C? [L1 < L2, and they point in the +z direction]
A 3000-kg car accelerates at a constant rate from rest to a speed of 27.0 m/s in 4.00 seconds on a horizontal road. What is the average power delivered by the car engine during this period?
A. 273 kW
B. 182 kW
C. 444 kW
D. 109 kW
E. 390 kW
What is A? [273kW]
A man applies a horizontal force (to the right) of magnitude 20N on a 4.0-kg crate, and the crate moves across a rough horizontal floor at a constant speed. The total work done on a crate as it moves a distance of 2.0m.
A. 4.0 J
B. 8.0 J
C. 0
D. 2.0 J
E. 6.8 J
What is C? [0]
A disk-like, metallic flywheel rotates, starting from rest, about a fixed axis through its center. The flywheel rotates at a constant rate of & = 1.2 rad/s? in the xy plane of a right-handed coordinate system, as shown in the figure viewed from the top. If the flywheel has a moment of inertia of / = 1.2 kg•m? for such rotations, the total kinetic energy (K) of the flywheel as it rotates through 10 revolutions.
A. 220 J
B. 90 J
C. 110 J
D. 180 J
E. 65 J
What is B? [90 J]
As shown, a man pushes a crate across a rough horizontal floor with a force of magnitude F at 21° with the horizontal. The crate moves at a constant speed, and the magnitude of the normal force on the crate from the floor is N = 350 N. If the coefficient of kinetic friction between the crate and the floor is ux =0.12, find the force.
A. 42 N
B. 110 N
C. 45 N
D. 39 N
E. 13 N
What is C? [45N]
The following free-body diagrams best represent the correct relative magnitudes and directions of the forces acting on a person(p) in an elevator that is moving downward but is gradually slowing down at a constant rate. Ffloor is the force by the floor on the person and w is the force of gravity on the person.
A.
B.
C.
D.
E.
What is B?
A box of mass M rests on the floor of an elevator. If the elevator accelerates downward with an acceleration of magnitude a = 0.50 g, what is the magnitude and direction of the normal force that the floor exerts on the box? Note: g is the acceleration due to gravity (magnitude only).
A. 1.5 Mg pointing upward
B. 1.5 Mg pointing downward
C. Mg pointing downward
D. 0.50 Mg pointing upward
E. 0.50 Mg pointing downward
What is D? [0.50 Mg pointing upward]
A 1.5-kg block resting on a horizontal frictionless surface is pushed against an ideal massless spring with force constant k = 1000 N/m to compress the spring by 5.0 cm from its equilibrium position (x = 0). If the block is released from rest, the speed of the block when the spring reaches the equilibrium position.
A. 0.98 m/s
B. 1.7 m/s
C. 1.9 m/s
D. 0.37 m/s
E. 1.3 m/s
What is E? [1.3m/s]
A disk-like, metallic flywheel rotates, starting from rest, about a fixed axis through its center. The flywheel rotates at a constant rate of a = 1.2 rad/s2 in the xy plane of a right-handed coordinate system, as shown in the figure viewed from the top. At a given time, the flywheel has angular velocity w. Identify the true statement.
A. w points in the -z direction; a points in the -z direction.
B. w points in the -z direction; a points in the +z direction.
C. w points in the +z direction; a points in the -z direction.
D. w points in the +z direction; a points in the +z direction.
E. w points in the +x direction; a points in the -x direction.
What is A? [w points in the -z direction; a points in the -z direction]