5. A sledgehammer of mass 12 kg is being used to drive a wooden post of mass 4 kg into the ground. A labourer moves the sledgehammer from rest at a point 0.5 m vertically above the post with constant acceleration \(16 \mathrm {~m} \mathrm {~s} ^ { - 2 }\) directed towards the post.

1. Find the velocity with which the sledgehammer hits the post. When the sledgehammer hits the post, they both move together with common speed, \(V\).
2. Show that \(V = 3 \mathrm {~ms} ^ { - 1 }\). As the sledgehammer hits the post, the labourer relaxes his grip and applies no further force. The sledgehammer and post are brought to rest by the action of a resistive force from the ground of magnitude 1500 N .
3. Find, in centimetres, the total distance that the sledgehammer and the post travel together before coming to rest.