When we first observe a wheel it is spinning clockwise at 30 rad/s, but when we observe it 10 seconds later it is spinning counterclockwise at 30 rad/s. (see figure) Assume that the wheel's angular acceleration is constant during the 10 second interval and that our point of view does not change. Assuming that the wheel continues with the same constant angular acceleration, what would its angular displacement be over the next 10 s interval (i.e., between 10 s and 20 s)?

Options

A. 0 rad
B. 300 rad
C. 450 rad
D. 600 rad

Answer

D

Explanation

`30=-30+alpha xx 10`
`alpha =6`
`theta=30xx10 +(1)/(2) xx 6 xx 10^(2)= 600` rad .