The ballistic pendulum is a device used to measure the speed of a projectile, such as a bullet. The projectile, of mass 5g, is fired into a large block (of wood or other material) of mass 1kg, which is suspended like a pendulum. As a result of the collision, the pendulum and projectile together swing up to a maximum height of 20cm, Figure below.
a) calculate the speed immediately after collision.
b) calculate the speed of the bullet before collision.