still haven't figured this one out, anyone?
A projectile (mass = 0.17 kg) is fired at and embeds itself in a target (mass = 2.03 kg).
The target (with the projectile in it) flies off after being struck.
What percentage of the projectile's incident kinetic energy does the target (with the projectile in it) carry off after being struck?
First off is this in two dimensions? How is the percentage calculated from elastic collision or momentum theorems?
thanks for any help.
(where M is the mass of the block, m is the mass of the bullet, V is the velocity of the bullet + block, and v is the incident velocity of the bullet.)
We want the bullet + block's kinetic energy. Thus
What fraction of the bullet's incident kinetic energy is this? Well, just before the collision the bullet had a kinetic energy of , so
and I'll let you plug the masses in from here.
Note that this result says there is no way to make this collision elastic.