Q1) A sphere and a cylinder of equal mass and radius are
simultaneously released from rest on the same inclined plane and
roll without sliding down the incline. Then:
1) the sphere reaches the bottom first because it has the greater
inertia
2) the cylinder reaches the bottom first because it picks up more
rotational energy
3) the sphere reaches the bottom first because it picks up more
rotational energy
4) they reach the bottom together
5) none of the above are true
Q2) Two cylinders of the same size and mass roll down an incline.
Cylinder A has most of its weight concentrated at the rim, while
cylinder B has most of its weight concentrated at the center.
Which reaches the bottom of the incline first?
1) A
2) B
3) Tie
Q3) Disks A and B are identical and roll across a floor with equal
speeds. Then disk A rolls up an incline, reaching a maximum
height h, and disk B moves up an incline that is identical except
that it is frictionless. Is the maximum height reached by disk B
greater than, less than, or equal to h?
1) greater than
2) less than
3) equal to
Q4) A hoop and a disk, each with the same mass M and same
radius R, race down a hill. Who wins? (Assume they roll without
slipping, and neglect rolling friction)
1) Hoop wins
2) Disk wins
3) Tie!
Q5) A sphere, a hoop, and a cylinder, all with the same mass M and same
radius R, are rolling along, all with the same speed v.
Sphere
Hoop
v
Disk
v
v
Which has the most kinetic energy?
1) Sphere
2) Hoop
3) Disk
4) All have the same KE.
Q6) A thin-walled hollow tube rolls without sliding along the
floor. The ratio of its translational kinetic energy to its rotational
kinetic energy (about an axis through its center of mass) is:
1) 1
2) 2
3) 3
4) 1/2
5) 1/3
Q7) A force F is applied to a dumbbell for a time interval t, first
as in (a) and then as in (b). In which case does the dumbbell
acquire the greater center-of-mass speed?
1) (a)
2) (b)
3) no difference
4) The answer depends on the rotational
inertia of the dumbbell.
Q8) A force F is applied to a dumbbell for a time interval t, first
as in (a) and then as in (b). In which case does the dumbbell
acquire the greater energy?
1) (a)
2) (b)
3) no difference
4) The answer depends on the rotational
inertia of the dumbbell.
Q9) Vector A is -2j and vector B is -3i. What is the direction of
B x A?
1) j
2) i
3) k
4) -k
5) -I
Q10) The position vector of a particle is directed along the positive
y axis. What is the direction of the net force acting on the particle
if the net torque is directed along the negative x direction?
1)
2)
3)
4)
5)
- x direction
+ x direction
- y direction
+ z direction
- z direction
Q11) A single force acts on a particle situated on the positive x
axis. The torque about the origin is in the negative z direction. The
force might be:
1) in the positive y direction
2) in the negative y direction
3) in the positive x direction
4) in the negative x direction
5) in the positive z direction
Q12) What is the vector product, A  B , if A  2.2iˆ  3.4 ˆj and
B  4.4iˆ  2.0 ˆj ?
1) zero
2) 10.6kˆ
3) 4.4iˆ  15.0 ˆj
4) 19.4kˆ
5) 8.3
Q13) The second hand on a clock completes one revolution each
minute. What is the direction of the angular momentum of the
second hand as it passes the “12” at the top of the clock?
1)
2)
3)
4)
5)
toward the “12”
toward the “3”
toward the “6”
outward from the face of the clock
into the face of the clock
Q14) A solid sphere of radius R rotates about an axis that is
tangent to the sphere with an angular speed . Under the
action of internal forces, the radius of the sphere increases to
2R. What is the final angular speed of the sphere?
1) /4
2) /2
3) 
4) 2
5) 4
Q15) A uniform sphere of radius R rotates about a diameter with
an angular momentum of magnitude L. Under the action of internal
forces the sphere collapses to a uniform sphere of radius R/2. The
magnitude of its new angular momentum is:
1) L/4
2) L/2
3) L
4) 2L
5) 4L
Q16) A child stands on the edge of a merry-go-round, which spins
without friction. The child slowly walks towards the center of the
platform. As the child moves toward the center, the platform's
rotation rate:
1) Increases
2) Decreases
3) Stays the same
Q17) A star is rotating with a period T. Over a period of a million
years, its radius decreases by a factor of 2. What is the new period
of the star? (Hint: I sphere  25 M R 2 )
1) T/2
4) T/4
2) 2T
5) None of these.
3) 4T
Q18) A rhinoceros beetle rides the rim of a small disk that rotates
like a merry-go-round. If the beetle crawls toward the center of the
disk, do the following (each relative to the central axis) increase,
decrease, or remain the same:
1) the rotational inertia of the beetle–disk system,
2) the angular momentum of the system, and
3) the angular speed of the beetle and disk?
Q19) A figure skater stands on one spot on the ice (assumed
frictionless) and spins around with her arms extended. When she
pulls in her arms, she reduces her rotational inertia and her angular
speed increases so that her angular momentum is conserved.
Compared to her initial rotational kinetic energy, her rotational
kinetic energy after she has pulled in her arms must be
1) the same.
2) larger because she’s rotating faster.
3) smaller because her rotational inertia is smaller.
Q20) A man, with his arms at his sides, is spinning on a light
frictionless turntable. When he extends his arms:
1) his angular velocity increases
2) his angular velocity remains the same
3) his rotational inertia decreases
4) his rotational kinetic energy increases
5) his angular momentum remains the same
Q21) A phonograph record is dropped onto a freely spinning turntable. Then:
1) neither angular momentum nor mechanical energy is conserved because of the
frictional forces between record and turntable
2) the frictional force between record and turntable increases the total angular
momentum
3) the frictional force between record and turntable decreases the total angular
momentum
4) the total angular momentum remains constant
5) the sum of the angular momentum and rotational kinetic energy remains constant
Q22) A 6.0-kg particle moves to the right at 4.0 m/s as shown. The
magnitude of its angular momentum about the point O is:
1) zero
2) 288 kg m2/s
3) 144 kg m2/s
4) 24 kg m2/s
5) 249 kg m2/s
Q23) A single force acts on a particle P. Rank each of the
orientations of the force shown below according to the magnitude
of the time rate of change of the particle's angular momentum
about the point O, least to greatest.
1) 1, 2, 3, 4
2) 1 and 2 tie, then 3, 4
3) 1 and 2 tie, then 4, 3
4) 1 and 2 tie, then 3 and 4 tie
5) All are the same