1. What is the force that opposes the motion of a body rolling on a surface called?
a) Sliding friction
b) Rolling friction
c) Fluid friction
d) Air resistance
2. What factors affect the magnitude of rolling friction?
a) Surface roughness and material
b) Velocity and mass
c) Temperature and humidity
d) All of the above
3. How does the coefficient of rolling friction compare to the coefficient of sliding friction?
a) It is always greater
b) It is always smaller
c) It is the same
d) It depends on the surfaces and materials involved
4. What type of surface typically has the lowest coefficient of rolling friction?
a) Rough concrete
b) Smooth steel
c) Rubber on asphalt
d) Sand on wood
5. How can the rolling friction of a wheel be reduced?
a) Increasing the tire pressure
b) Decreasing the tire pressure
c) Using a harder tire material
d) Using a softer tire material
6. What type of wheel is most commonly used to reduce rolling friction?
a) Solid wheel
b) Pneumatic wheel
c) Spoked wheel
d) Metal wheel
7. What is the name of the device that is used to measure the coefficient of rolling friction?
a) Rolling friction tester
b) Friction force sensor
c) Rolling resistance meter
d) Friction coefficient gauge
8. How does the rolling friction of a ball bearing compare to that of a sliding bearing?
a) It is always greater
b) It is always smaller
c) It is the same
d) It depends on the surfaces and materials involved
9. In what type of application would the rolling friction be more important than the sliding friction?
a) A car driving on a smooth road
b) A skateboarder performing a trick
c) A train running on tracks
d) A boat sailing on a lake
10. How does the rolling friction of a wheel change with the speed of the wheel?
a) It increases
b) It decreases
c) It remains the same
d) It depends on the surfaces and materials involved
Answers:
- b
- d
- b
- b
- a
- b
- c
- b
- c
- c