(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

David used a sling to kill Goliath. The mass of the rock was 2.5 kg and the sling had a length of 1.2 m. If it spun horizontally 2 m above his head 7 times in 3 seconds:

a. What was the launch velocity?

b. What is the centripetal force and tension?

c. How far is David from Goliath?

2. Relevant equations

Fc=mv^2/r

F=ma

Fc=m4(pi^2)r/t^2

3. The attempt at a solution

I tried setting ma=mv^2/r, but that would only give me the velocity it spins at, not the velocity at which it was launched. And I'm not sure what to do with the 2 m.

Assistance would be great, I've been trying this for 2 hours and still nothing.

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# Homework Help: Help on this would be amazing; centripetal force & projectile motion

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