3. A. 50kg rock is tied on a 1.0m string which has a breaking force of 990N. If the string breaks,

what is the speed of the rock?

The velocity of the stone is, v = 4.45 m/s

Explanation:

Given data,

The mass of the rock, m 50 kg

The length of the string, r = 1.0 m

The breaking force of the string, F = 990 N

If the rotated in a circular motion with the string, the string breaks when the centripetal force exceeds 990 N.

The centripetal force is given by the formula,

F = mv² / r

∴ v = √ (Fr/m)

= √ (990 x 1 / 50)

= 4.45 m/s

Hence, the velocity of the stone is, v = 4.45 m/s