Question

A coin completes 18 spins in 12 seconds. The centripetal acceleration of the edge of the coin is 2.2 m/s2. The radius of the coin is ____-blank

Answer 1

Answer:

0.025 m

Explanation:

The coin completes 18 revolutions in 12 seconds. The angular velocity of the coin is:

$\omega = \frac{18 rev}{12 s} \cdot (2\pi \frac{rad}{rev})=9.42 rad/s$

The centripetal acceleration of the edge of the coin is given by

$a=\omega^2 r$

where we have

a = 2.2 m/s^2 is the acceleration

r is the radius of the coin

Solving for r, we find

$r=\frac{a}{\omega^2}=\frac{2.2 m/s^2}{(9.42 rad/s^2)^2}=0.025 m$