1) A circular disk 0.20m in diameter starts from rest and accelerates with constant angular acceleration to an angular acceleration to an angular velocity of 210 rad/s in 10.00s. Find the angular acceleration and the angle which the disk has turned in degrees.

Question

2) A car with tires of radius 32cm drives on the highway at 60km/h. What is the angular speed of the tires.

Answer 1

1. a = (V-Vo)/t = (210-0)/10 =21rad/s^2.

d = 0.5a*t^2 = 0.5*21*10^2 = 1050 Rad.

A = 1050rad * 360o/6.28 = 50,134 Deg..

2. C = pi*2r = 3.14 * 64cm=201 cm=2.01m
= Circumference.

V = 60km/h = 60000m/3600s = 16.67 m/s.

Va = 16.67m/s * 6.28rad/2.01m=52 rad/s.
= Angular velocity.