Physics
posted by Physics on .
A 0.400 kg block of wood hangs from the ceiling by a string, and a 0.0700 kg wad of putty is thrown straight upward, striking the bottom of the block with a speed of 6.40 m/s. The wad of putty sticks to the block.
How high does the puttyblock system rise above the original position of the block?
I'm confused as to what equation to use. None of them seem to fit the bill perfectly.

I have solved this problem.

use conservation of momentum to get the velocity of the block/putty after collision. Then, using that initial vertical velocity, compute the altitude
vi^2=2g*height