which produces greater friction .............. a-Rougher surfaces b-smooth surfaces.

What is the type of force when 2 surfaces rub together?

Factors affect the friction force . a-type of surfaces b-The weight c-both

Which of the following is an example of friction that is helpful? a-Brakes used on a bike          b-Tires from a car on the road        c-Tread on the bottom of your shoes      d-All are examples that are helpful

True or False: Friction speeds up moving objects.

Is a force that works against motion between object & medium touching.

hich of these materials do you predict would have the MOST amount of friction, Sand paper or Tile?

Friction is a force that acts in an ___________ direction of movement. a-similar b-opposite

True or false :Friction can make things slow down or stop.