Question

1. which type of friction is responsible for stopping a moving hockey puck on the ice?

a) rolling friction
b) static friction
c) sliding friction
d) fluid friction

1. which friction is the strongest?

a) fluid friction
b) static friction
c) sliding friction
d) rolling friction

1. which of the following is an example of fluid friction?

a) brakes stopping a car
b) a ball rolling on a field
c) a swimmer moving through water
d) a box sitting still on a shelf

1. why do wheels help reduce the amount of force needed to move an object?

a) they increase static friction
b) they use rolling friction, which is weaker
c) they completely remove friction
d) they create fluid friction

Explanation:

1. Sliding friction acts when two surfaces slide over each other. A hockey puck sliding on ice experiences sliding friction which stops it.
2. Static friction is the force that keeps an object at rest. It is the strongest among the given frictions as it needs to be overcome first for an object to start moving.
3. Fluid friction occurs when an object moves through a fluid (liquid or gas). A swimmer moving through water experiences fluid friction.
4. Rolling friction is weaker than sliding friction. Wheels use rolling friction, so less force is needed to move an object compared to sliding.

Answer:

1. c) Sliding friction
2. b) Static friction
3. c) A swimmer moving through water
4. b) They use rolling friction, which is weaker