FRICTION

Friction is an example of _____________

• contact force

• non contact force

• both of these

• none of these

The direction of force of friction is always _____ to the direction of motion

• same

• opposite

• unchanged

• none of these

Without friction, an object in motion would never stop.

• true

• false

Frictional force depends on ____

• surface area in contact

• roughness of surface

• both a and b

• none of the above

Which of these materials do you predict would have the MOST amount of friction?

• metal

• tile

• sand paper

• denim

The rouugher the surface, the faster an object will travel over the surface

• true

• false

How would the absence of friction affect a marble travelling on a long, straight path?

• the marble's speed would decrease

• the marble would remain at a constant speed

• the marble's speed would increase

• the marble would stop immediately

The amount of friction depends on the weight of the objects pressing together

• false

• true

Rough surfaces have _________

• greater friction

• less friction

• the same level of friction

When we rub our hands together _________.

• frictional force works between them

• energy is released

• our hands become warm

• all off the above