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

Friction is a ..............................force a-contact b- noncontact

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

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

Is a push or a pull

1. 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

A force that pushes or pulls an object without touching it.

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

A type of friction that occurs when air pushes against a moving object causing it to negatively accelerate surface area a-air resistance b-decreasing velocity c-gravity

magnetism, gravity and electrostatic forces. a-non Contact Force b-Contact Force

........................ Is a push or a pull applied by one object to another object that is touching it.

The measuring unit of force is the ........................