Deck 2: Gravitation, Force, Motion, Equilibrium, Elasticity, Rotation, Center of Mass, Linear Momentum, Potential Eneray, Conservation of Energy, Kinetic Energy, Work, Rolling, Torque, and Angular Momentum

Question 1

A particle might be placed
1) inside a uniform spherical shell of mass M, but not at the center
2) inside a uniform spherical shell of mass M, at the center
3) outside a uniform spherical shell of mass M, a distance r from the center
4) outside a uniform solid sphere of mass M, a distance 2r from the center
Rank these situations according to the magnitude of the gravitational force on the particle, least to greatest.

A) All tie
B) 1, 2, 3, 4
C) 1 and 2 tie, then 3 and 4 tie
D) 1 and 2 tie, then 3, then 4
E) 1 and 2 tie, then 4, then 3

Answer 1

1 and 2 tie, then 3, then 4

Question 2

The fundamental dimensions of angular momentum are:

A) mass·length·time^-1
B) mass·length^-2·time^-2
C) mass·²·time^-1
D) mass·length²·time^-2
E) none of these

Answer 2

none of these

Question 3

If a wheel is turning at 3.0 rad/s, the time it takes to complete one revolution is about:

A) 0.33 s
B) 0.67 s
C) 1.0 s
D) 1.3 s
E) 2.1 s

Answer 3

2.1 s

Question 4

The fan shown has been turned on and is slowing as it rotates clockwise. The direction of the acceleration of the acceleratrion point X on the fan tip could be:

A)
B)
C) $\downarrow$
D) $\leftarrow$
E) $\rightarrow$

Question 5

A meter stick on a horizontal frictionless table top is pivoted at the 80-cm mark. A horizontal force is applied perpendicularly to the end of the stick at 0 cm, as shown. A second horizontal force (not shown) is applied at the 100-cm end of the stick.If the stick does not rotate:

A) for all orientations of
B) for all orientations of
C) for all orientations of
D) for some orientations of for others
E) for some orientations of for others

Question 6

A small disk of radius R₁ is mounted coaxially with a larger disk of radius R₂. The disks are securely fastened to each other and the combination is free to rotate on a fixed axle that is perpendicular to a horizontal frictionless table top,as shown in the overhead veiw below. The rotational inertia of the combination is I. A string is wrapped around the larger disk and attached to a block of mass m, on the table. Another string is wrapped around the smaller disk and is pulled with a force as shown. The acceleration of the block is:

A) R₁F/mR₂
B) R₁R₂F/(I - mR² ₂)
C) R₁R₂F/(I + mR² ₂)
D) R₁R₂F/(I - mR₁R ₂)
E) R₁R₂F/(I + mR₁R ₂)

Question 7

A small disk of radius R₁ is fastened coaxially to a larger disk of radius R₂. The combination is free to rotate on a fixed axle, which is perpendicular to a horizontal frictionless table top, as shown in the overhead veiw below. The rotational inertia of the combination is I. A string is wrapped around the larger disk and attached to a block of mass m, on the table. Another string is wrapped around the smaller disk and is pulled with a force as shown. The tension in the string pulling the block is:

A) R₁F/R₂
B) mR₁R₂F/(I - mR²₂)
C) mR₁R₂F/(I + mR²₂)
D) mR₁R₂F/(I - mR₁R ₂)
E) mR₁R₂F/(I + mR₁R ₂)

Question 8

The x and y coordinates in meters of the center of mass of the three-particle system shown below are:

A) 0, 0
B) 1.3 m, 1.7 m
C) 1.4 m, 1.9 m
D) 1.9 m, 2.5 m
E) 1.4 m, 2.5 m

Question 9

The center of mass of a system of particles obeys an equation similar to Newton's second law where:

A) is the total internal force and m is the total mass of the system
B) is the total internal force and m is the mass acting on the system
C) is the total external force and m is the total mass of the system
D) is the force of gravity and m is the mass of Earth
E) is the force of gravity and m is the total mass of the system

Question 10

A simple pendulum consists of a 2.0 kg mass attached to a string. It is released from rest at X as shown. Its speed at the lowest point Y is:

A) 0.90 m/s
B)
C) 3.6 m/s
D) 6.0 m/s
E) 36 m/s

Question 11

Objects A and B interact with each other via both conservative and nonconservative forces. Let K_A and K_B be the kinetic energies, U be the potential energy, and E_int be the internal energy. If no external agent does work on the objects then:

A) K_A + U is conserved
B) K_A + U + E_int is conserved
C) K_A + K_B + E_int is conserved
D) K_A + K_B + U is conserved
E) K_A + K_B + U + E_int is conserved

Question 12

Three identical springs (X,Y,Z) are arranged as shown. When a 4.0-kg mass is hung on X, the mass descends 3.0 cm. When a 6.0-kg mass is hung on Y, the mass descends:

A) 2.0 cm
B) 4.0 cm
C) 4.5 cm
D) 6.0 cm
E) 9.0 cm

Question 13

The speed of a 4.0-N hockey puck, sliding across a level ice surface, decreases at the rate of 0.61 m/s². The coefficient of kinetic friction between the puck and ice is:

A) 0.062
B) 0.41
C) 0.62
D) 1.2
E) 9.8

Question 14

A heavy wooden block is dragged by a force along a rough steel plate, as shown below for two possible situations. The magnitude of is the same for the two situations. The magnitude of the frictional force in (ii), as compared with that in (i) is:

A) the same
B) greater
C) less
D) less for some angles and greater for others
E) can be less or greater, depending on the magnitude of the applied force.

Question 15

Two blocks (A andB) are in contact on a horizontal frictionless surface. A 36-N constant force is applied to A as shown. The magnitude of the force of A on B is:

A) 1.5 N
B) 6.0 N
C) 29 N
D) 30 N
E) 36 N

Question 16

A particle goes from x = -2 m, y = 3 m, z = 1 m to x = 3 m, y = -1 m, z = 4 m. Its displacement is:

A)
B)
C)
D)
E)