Acoin 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?

24.8 mm

Explanation:

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

(1)

where

is the angular frequency

r is the radius of the coin

The frequency of revolution of the coin is equal to the number of spins divided by the time taken:

And the angular frequency is given by

Since we know the centripetal acceleration, , we can re-arrange eq.(1) to find the radius of the coin:

305.7

explanation:

density =m/v

density =917/3.00

density = 305.

approximately = 305.7

in four significant figures