5-3 A Car Rounding a Curve•An example of centripetal

acceleration occurs when an automobile rounds a curve.

•When you round a curve, you feel pushed out, but there is no force pushing you out, you are showing

inertia…the seat (by friction) and/or the door (by contact) exert an inward

force on you.

See Example 5-7

•F=ma= mv2 /r •to solve skidding curve problems.

Cars on a banked curve…

• FN =sin F = m v2 / r• See Example 5-8 page 121

5-4 Nonuniform Circular Motion

• Circular, uniform motion occurs when the net force is exerted towards the center of the circle…when the net force is a blend of linear and centripetal acceleration, this is nonuniform circular motion.

See example 5-9 page 122

• Remember…forces and resultant accelerations have the same direction…see the diagram p 122.

• Use atan = Dv/Dt and ac =v2 /r and the addition of vectors in combination with the Pythagorean theorem to solve nonuniform circular motion problems.

Homework due Monday BOP

•Page 140 10-14, 17,22-23