Question

An athlete twirls a 9 kg hammer tied to the end of a 1.3-m rope horizontally about his head. The hammer moves at 40.84 m/s. What is the force of tension in the rope?

Answer 1

It's in circular motion, therefor undergoing centripetal acceleration, where the only force is the Tension of the rope.

\[ \sum F = T = ma_{cent}\]
\[T=m\frac{v^2}{r}\]

Answer 2

where r is the length of the rope

^_^