An invading barbarian whirls a stone in a leather sling. If the sling is 90 cm long, and the velocity of the stone is 90 m/s, what is the centripetal
acceleration of the stone?

Explanation:

Centripetal acceleration is expressed as shown:

a = v²/r

v is the velocity

r is the radius

If the length of the sling is 90cm, hence the circumference of the circular path is 90cm

Since C = 2πr

0.9 = 2πr

r = 0.9/2π

r = 0.9/2(3.14)

r = 0.9/6.28

r = 0.143m

Get the centripetal acceleration:

a = 90²/0.143

a = 56,643.36m/s²

Hence the the centripetal  acceleration of the stone is  56,643.36m/s²