| 1. |
Which of the following diagrams shows the instantaneous velocity v
and centripetal force F for an object in uniform circular motion.
|
| 2. |
A 1.2 m long pendulum reaches a speed of 4.0 m/s at the bottom of its
swing.
What is the tension in the string at this position?
| A. 11 |
B. 29 N |
C. 40 N |
D. 69 N |
|
| 3. |
A 1200 kg car rounds a flat circular section of road at 20 m/s as shown
in the diagram.
The coefficient of friction between the car tires and the road surface
is 0.65. What minimum friction force is required for the car to follow
this curve?
| A. 3.7 × 10 3 N |
B. 5.6 × 10 3 N |
C. 7.6 × 10 3 N |
D. 1.2 × 10 4 N |
|
| 4. |
A 65 kg student is in a car travelling at 25 m/s on a hill of radius
110 m. When the car is at the top of the hill, what upward force does the
seat exert on the student?
| A. 270 N |
B. 370 N |
C. 640 N |
D. 910 N |
|
| 5. |
An object attached to a rotating table is moving in a circular path
with a constant speed.
Which is the correct free body diagram for the object?
|
| 6. |
An object travels with a constant speed in a circular path. The net
force on the object is
A. zero.
B. towards the centre.
C. away from the centre.
D. tangent to the object's path. |
| 7. |
A car moving in a circular path with a constant speed has
A. no acceleration.
B. outward acceleration.
C. tangential acceleration.
D. centripetal acceleration. |
| 8. |
A person is moving at constant speed in a vertical circular path.
Which is the correct free body diagram for the person while passing
through the lowest point?
|
| 9. |
A 61 kg skateboarder is moving down a ramp with
a 7.0 m radius of curvature. At the bottom of this ramp he reaches a speed
of 7.8 m/s.
What upward force acts on the skateboarder at the bottom of the ramp?
| A. 7.0 × 10 1 N |
B. 5.3 × 10 2 N |
C. 6.0 × 10 2 N |
D. 1.1× 10 3 N |
|
| 10. |
A 9.0 × 10 -3 kg ball is attached
to a 3.6 × 10 -2 kg mass M by a string
that passes through a hole in a horizontal frictionless surface. The ball
travels in a circular path of radius 0.35 m.
What is the speed of the ball?
| A. 0.93 m/s |
B. 1.9 m/s |
C. 3.7 m/s |
D. 4.1 m/s |
|
| 11. |
Hans, whose mass is 50 kg, rides on a ferris
wheel in a circular path at constant speed. When he is at the top of the
wheel, the seat exerts an upward force of 420 N on Hans.
What is the centripetal force on Hans at the top of the wheel?
| A. 70 N |
B. 420 N
|
C. 490 N
|
D. 910 N
|
|
| 12. |
A 1.2 kg mass on the end of a string is rotated in a vertical circle
of radius 0.85 m.
If the speed of the mass at the top of the circle is 3.6 m/s, what is
the tension in the string at this location?
| A. 6.5 N |
B. 12 N |
C. 18 N |
D. 30 N |
|
| 13. |
An object of mass m is on a horizontal rotating platform. The
mass is located 0.22 m from the axle and makes one revolution every 0.74
s.
The friction force needed to keep the mass from sliding is 13 N. What
is the object's mass?
| A. 0.82 kg |
B. 1.3 kg |
C. 2.7 kg |
D. 5.2 kg |
|
| 14. |
A bus of weight g is moving at a constant speed over over a hill and
dip that have the same radius of curvature.
When the bus is passing over the crest of the hill, the road exerts
a normal force on the bus equal to three quarters of the bus's weight (3/4
Fg) . What is the normal force the road
exerts on the bus when the bus is passing through the bottom of the dip?
| A. 1/4 Fg |
B. 3/4 Fg |
C. 5/4 Fg |
D. 7/4 Fg |
|
| 15. |
A child is riding on a merry-go-round which is rotating at a constant
rate. Which of the following describes the child's speed, velocity, and
magnitude of acceleration?
|
SPEED
|
VELOCITY
|
MAGNITUDE OF ACCELERATION
|
| A. |
constant
|
constant
|
constant
|
| B. |
constant
|
changing
|
constant
|
| C. |
changing
|
constant
|
changing
|
| D. |
changing
|
changing
|
changing
|
|
| 16. |
A 3.5 kg object is suspended by a string and moves in a horizontal
circle of radius 0.60 m. The tension in the string is 36 N.
a) What is the magnitude of the net force on the object? (3 marks)
b) What is the period of revolution of the object? (4 marks) |
| 17. |
A 6.1 kg object on the end of a massless connecting rod moves in uniform
circular motion in a vertical circle with radius 1.2 m. The period of revolution
is 0.80 s.
a) Calculate the tension in the connecting rod at this position. (7
marks) |
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