Posted by joey on Thursday, December 9, 2010 at 3:22pm.
A bullet of mass 8 g strikes a ballistic pendulum of mass 2.0 kg. The center of mass of the pendulum rises a vertical distance of 10 cm. Assuming that the bullet remains embedded in the pendulum, calculate the bullet's initial speed.

physics  bobpursley, Thursday, December 9, 2010 at 3:29pm
The momentum of the bullet: massbullet*velocity
that has to equal the momentum of the block and bullet combination at impact(mblock+massbullet)V set them equal, and solve for V.
Now, the initialKE of the block and bullet combination is 1/2 (totalmass)V^2
set that equal to the change in PEnergy
totalmass*g*height.
solve for height in terms of initial bullet velocity.
WEll, you know height, so you can solve for bullet velocity. 
physics  Anonymous, Friday, November 11, 2016 at 8:31pm
12