# Find the recoil velocity of the nucleus.

## Homework Statement

An alpha particle is emitted from a stationary nucleus at $$1.8 \times 10^7 ms^{-1}$$.The mass of the particle is $$4u$$ and that of the nucleus is $$212u$$. (u is a unit of mass equal to $$1.66 \times 10^{-27}kg$$.)
(a) Find the recoil velocity of the nucleus.
(b) Explain how you know the direction of movement.

## Homework Equations

Momentum before collision = Momentum after collision

## The Attempt at a Solution

What does recoil velocity mean?