Question

You have a ball with mass 2.8 kg tied to a rope, and you spin it in a circle of radius 1.3 m. If the ball is moving at a speed of 7 m/s, what is the centripetal force acting on the ball?

Answer 1

According to Newton's second law:

F=ma=m*v^2/R=2.8*7^2/1.3=105.54 N

Answer 2

Centripetal force;

`= \frac{m {v}^(2) }{r}`

`= \frac{2.8 * {7}^(2) }{1.3}`

`= (2.8 * 49)/(1.3) \\ \\ = (137.2)/(1.3) = 105 \: newtons`