Question

10. Use the equations of rotational kinematics to calculate the angular acceleration needed to increase the angular velocity of the spinning stopper from 10 rad/s to 20 rad/s in a time of 8 seconds. How many revolutions would the stopper complete in that time?

the stopper is .31 g

Answer 1

$\alpha=\frac{20-10}{8}=1.25 rad/s \\ \theta=\frac{1}{2}\alpha t^2=1.25*0.5(8)^2=40 radians \\ =\frac{40}{2 \pi} \approx 6$

Answer 2

Answer 3

angular acce = change in ang vel/time

= 10/8

= 1.25 rad/sec^2

b) 20^2 - 10^2 = 2*1.25*s

s = 120 rad

= 19.098 revolutions