Download AP Physics Circular Motion MC Sample

AP Physics
1.
2.
Circular Motion
A car moving at 10 m/s makes a 90o turn that has a radius
of 20 m. How long does this 90o turn take?
(A) 0.25π seconds
(B) 0.5π seconds
(C) π seconds
(D) 2π seconds
(E) 4π seconds
5.
A mass moves in uniform circular motion with a radius of
1 m. The frequency of this motion is 0.5 Hz. The objects
centripetal acceleration is
(A) 0.25π 2 m/s2
(B) 0.5π 2 m/s2
(C) π 2 m/s2
(D) 2π 2 m/s2
(E) 4π 2 m/s2
6.
In uniform circular motion, which vectors point toward the
center of the circle?
(A) Centrifugal acceleration and centrifugal force.
(B) Centrifugal acceleration and centripetal force.
(C) Centripetal acceleration and centrifugal force.
(D) Centripetal acceleration and centripetal force.
(E) Velocity.
7.
An object is moving in uniform circular motion. If the
speed is doubled and the radius doubled the force and
acceleration will
(A) double.
(B) be cut in half.
(C) not change.
(D) quadruple.
(E) will be 2 time larger.
8.
When one object, mass m, orbits another it is the gravity
of the central object that provides the centripetal force. If
the orbiting object is a distance r from the central object,
what is its speed?
(A) zero
rg
(B)
When the tire of a car is rolling it comes into contact with
the road at the point shown. Which vector below depicts
the instantaneous velocity at this point?
(A)
(D)
(B)
(E)
zero.
(C)
3.
A mass is moving in a circle as shown above. The motion
is uniform, having constant speed. At the position
indicated by the dot, which set of vectors below are
consistent with uniform circular motion?
(A)
(D)
v
v
ac
(B)
(E)
v
ac
v
ac
ac
(C)
v
4.
ac
An airplane traveling at 100 m/s completes a maneuver
where it moves in a circle of radius 200 m at constant
speed. How many g’s of accelerations does the jet and
pilot experience?
(A) 1 g
(B) 2 g
(C) 3 g
(D) 4 g
(E) 5 g
MC Sample
(C)
2rg
(D) 2rg
(E) 2mrg
9.
A rollercoaster, mass m, just barely completes a loop.
What is the speed at the top of the loop?
(A) zero
(B)
rg
2rg
(C)
(D) 2rg
(E) 2mrg
10. How fast must a rollercoaster be moving at the top of the
loop so that the occupants feel weightless?
(A) zero
(B)
rg
(C)
2rg
(D) 2rg
(E) 2mrg
11. A car completes a turn of radius 20 m at a uniform speed
of 10 m/s. What minimum coefficient of friction can the
tires have?
(A) 0.1
(D) 0.5
(B) 0.2
(E) 1.0
(C) 0.4
12. A 10 kg mass travels at a uniform 5 m/s in a circle of
radius 2 m. What work is done on the mass?
(A) Zero
(D) 20 J
(B) 5 J
(E) 40 J
(C) 10 J
13. A mass is tied to a 1 m string. The string is attached to a
point on a horizontal frictionless surface and the mass is
set into circular motion. The string will break if tension
becomes larger than 10 N. The maximum kinetic energy
that the mass can achieve before the string breaks is
(A) 2 J.
(B) 5 J.
(C) 10 J.
(D) 20 J.
(E) 40 J.
14. Unbalanced torques cause objects to
(A) remain stationary
(B) rotate at uniform speed.
(C) rotate with changing speed.
(D) accelerate linearly.
(E) None of these.
1.
2.
3.
4.
C
E
B
E
5.
6.
7.
8.
C
D
A
B
15. You are trying to turn a stubborn bolt with a wrench. To
finally get the bolt moving you must apply three times the
force and double the length of the wrench handle without
changing the angle that the force is applied. Torque was
increased by a factor of
(A) It stayed the same.
(B) 2
(C) 3
(D) 6
30 cm
10 cm
20 cm 10 cm
M
1 kg
2 kg
16. A mobile, shown above, has three hanging masses. The
horizontal lines in the diagram represent massless rods.
The vertical lines in the diagram represent strings
supporting the three masses and the massless rods. The
distances shown are the measurements along each rod
from the string holding the rod up to the end of the rod on
the side that the measurement is shown. Solve for the mass
M that will balance the mobile.
(A) 1 kg
(B) 2 kg
(C) 3 kg
(D) 6 kg
(E) 9 kg
9.
10.
11.
12.
B
B
D
A
13.
14.
15.
16.
B
C
D
E