(adsbygoogle = window.adsbygoogle || []).push({}); A 5.00 g bullet is fired into a 6.00 kg block, which is suspended from a string 1.00 m long.

The string deflects through an angle of 12.0°. How fast was the bullet moving?a

Transitional KE = ½ mv2

Rotational KE = ½ I2 Elastic PE = ½k L 2

I'm not sure those are the right formulas even...

I'm not really sure what to do with the angle..For the left of the equation, I know that the first mass is the bullet's mass and the block's mass, but the block's mass will be ignored because it was not moving originally. For the right of the equation, the mass will be combined and the final velocity will be... I think the angle has something to do with the final velocity but somehow I can't figure out in any way how to deal with it.

Thank you for your help.. please help me!

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Momentum and Energy related Bullet Question!

**Physics Forums | Science Articles, Homework Help, Discussion**