A 3.5 g dart is fired into a block of wood with a mass of 22.8 g. The wood block is initially at rest on a 1.3 m tall post. After the collision, the wood block and dart land 2.6 m from the base of the post. Find the initial speed of the dart.

Question

A 3.5 g dart is fired into a block of wood with a mass of 22.8 g. The wood block is initially at rest on a 1.3 m tall post. After the collision, the wood block and dart land 2.6 m from the base of the post. Find the initial speed of the dart.
  m/s