Chapter 3.3 Friction

Question #1 Friction is resistance force. Friction is defined as the force that opposes the sliding or rolling motion of two surfaces that are in contact.

Question #2 The two factors that friction is dependent upon are the composition of the materials the roughness of the surfaces of the materials

A CLOSER LOOK: SANDPAPER The rougher the surface, the ______________ the friction. greater Friction is caused by the irregularities in the surfaces of objects that are touching. Even very smooth surfaces have microscopic irregularities that obstruct motion.

Question #3 Friction increases when the two surfaces pushed together with more force. This increases the strength of the microwelds. Friction can also increase as the roughness of the surfaces increases.

Question #4 Static friction (prevents two surfaces in contact from sliding or rolling past each other) Sliding friction (force acts in the opposite direction to the motion of the object causing it to slow down) Rolling friction (force resists rolling causing it to slow down-- similar to sliding but usually much less than sliding)

HOW DOES THE SURFACE INFLUENCE FRICTION? sliding rolling sliding

WHICH TYPE OF FRICTION? rolling sliding

WHICH TYPE OF FRICTION? rolling sliding

Question #5 For objects at rest, the applied force must be strong enough to break the microwelds. After the microwelds are broken, the object requires less force to overcome sliding friction. n/default.htm n/default.htm