At what angle (relative to the horizontal) should a curve 52.0 m in radius be banked if no friction is required to prevent the car from slipping when traveling at 11.6 m/s? (g = 9.80 m/s2)
a. 0.264
b. 1.30
c. 14.8
d. 2.59
[Ques. 2] A 1 500-kg car rounds an unbanked curve with a radius of 52 m at a speed of 12.0 m/s. What minimum coefficient of friction must exist between the road and tires to prevent the car from slipping? (g = 9.8 m/s2)
a. 0.024
b. 0.23
c. 0.28
d. 1.2
[Ques. 3] What centripetal force does an 80.0-kg passenger experience when seated 10.0 m from the center of a Ferris wheel whose angular speed is 0.500 rad/s?
a. 2.00 N
b. 24.5 N
c. 400 N
d. 200 N
[Ques. 4] Calculate the linear speed due to the Earth's rotation for a person at a point on its surface located at 60.0 N latitude. The radius of the Earth is 6.40 106 m.
a. 403 m/s
b. 233 m/s
c. 37.0 m/s
d. 74.1 m/s
[Ques. 5] Pierre performs a maneuver with his yo-yo called around the world, where he swings the yo-yo in a vertical circle. When the yo-yo is at its highest point, which forces provide the centripetal acceleration?
a. friction
b. gravity
c. normal force
d. tension
e. Two of the above choices are correct.
[Ques. 6] A wheel is rotated about a horizontal axle at a constant angular speed. Next it is rotated in the opposite direction with the same angular speed. The acceleration at a point on the top of the wheel in the second case as compared to the acceleration in the first case:
a. is in the same direction.
b. is in the opposite direction.
c. is upward.
d. is tangential to the wheel.
[Ques. 7] Consider a point on a bicycle tire that is momentarily in contact with the ground as the bicycle rolls across the ground with constant speed. The direction for the acceleration for this point at that moment is:
a. upward.
b. down toward the ground.
c. forward.
d. at that moment the acceleration is zero.
[Ques. 8] A 0.30-m-radius automobile tire accelerates from rest at a constant 2.0 rad/s2 over a 5.0-s interval. What is the tangential component of acceleration for a point on the outer edge of the tire during the 5.0-s interval?
a. 33 m/s2
b. 6.7 m/s2
c. 0.60 m/s2
d. 0.30 m/s2
[Ques. 9] A ventilation fan has blades 0.25 m in radius rotating at 20 rpm. What is the tangential speed of each blade tip?
a. 0.020 m/s
b. 0.52 m/s
c. 5.0 m/s
d. 20 m/s
[Ques. 10] In order to train for a high-g environment, an astronaut is placed in a centrifuge of radius several meters and rotated in a horizontal circle at constant speed. In this situation, in which direction is the net force on the astronaut?
a. The net force is down since gravity cannot be turned off.
b. The net force is horizontal toward the center of the circle.
c. The net force is between horizontal toward the center of the circle and straight up, the angle depending on the speed and the radius involved.
d. The net force is zero since the astronaut is moving at constant speed and thus the force has no direction.
Quick Reply
