1. Entry:
Date:
Friction Pg
8P2A1

2. Friction
A. is a force (push or pull)
B. occurs when two objects touch.
C. acts to resist sliding between two surfaces.

3. D. acts in the opposite direction to the force causing the motion.
E. can slow down or stop the motion.

4. F. If friction could be removed, objects in motion would stay in motion, in a straight line, and at a constant speed
I. Example: a satellite orbiting in space. There is no friction in space to change the motion.

5. 2. Static friction A. occurs when two objects touch, prevents motion.
B. force must be great enough to overcome static friction to start motion.

6. 3. Factors that determine the amount of friction
A. type of surface
Rough surface = harder to move
B. amount of force applied between the two surfaces
I More force needed to move heavy objects

7. 4. How to reduce friction A. smoother surface = less friction
B. wheels or rollers = less friction
C. Using oil, water, soap, air (fluid) = less friction
D. reduce the mass of the object
Video on Friction

8. 5. Air resistance
A. Is a fluid friction that occurs when an object moves through air
B. works in the opposite direction of gravity when an object is falling
C. if air resistance was ignored then everything would fall at the same speed
D. air resistance is why parachutes slow a person down video
Air resistance is the frictional force air exerts against a moving object. As an object moves, air resistance slows it down. The faster the object's motion, the greater the air resistance exerted against it.