1) An object of mass m is
on a horizontal rotating platform. The mass is located 0.22 m from the center 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?
2) An object travels along
a path at constant speed. There is a constant net force acting on the object that
remains perpendicular to the direction of the motion. Describe the path of the
object.
a) linear
b) circular
c) elliptical
d) parabolic
3) A child
is riding on a merry-go-round rotating at a constant rate. Which of the following
describes the child's speed, velocity, and magnitude of acceleration?
|
speed |
velocity |
acceleration |
| a) |
constant |
constant |
constant |
| b) |
constant |
changing |
constant |
| c) |
changing |
constant |
changing |
| d) |
changing |
changing |
changing |
 |
4) A 150 g
ball at the end of a string is revolving uniformly in a horizontal circle of radius 0.600
m. the ball makes exactly 2.00 revolutions in a second. What is its centripetal
acceleration?
5) How
large must the coefficient be between the tires and the road if a car is to round a level
curve of radius 95 m at a speed of 90 km/h?
6) A ball
attached to a string swings in a circle of radius 1.20 m at 28o angle with the
vertical. The tension in the string is 1.80 N.
a) What is
the mass of the ball?
b) How long does the ball take to complete one orbit?
7) A 35 kg
child spins in a 12 m radius vertical Ferris Wheel moving at constant speed; it completes a
full rotation every 9 seconds.
a) as the child
reaches the top, what is the magnitude of the force that the seat exerts on the child?
b) the magnitude of the child's acceleration at the top of the ride
compared to the child's acceleration at the bottom:
a) less than the bottom
b) greater than the bottom
c) same
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