Question

A 2.2 kg brick is dropped from a height of 1.0 m onto a small nail stuck vertically in a piece of wood. Assuming the nail does not move in to a large extent, how much heat is produced in the system when the block hits and sticks onto the top of the nail. (You can assume all of the energy becomes thermal energy gained by the nail.)

Answer 1

Mass of the brick, m = 2.2 kg

Height from which the brick is dropped, h = 1.0 m

Acceleration due to gravity, g = 9.8 m/s²

Potential energy of the brick, Ep = mgh = 2.2 x 9.8 x 1 = 21.56 J

The potential energy of the brick converts into kinetic energy as the brick is falling. The whole kinetic energy of the brick turns into thermal energy when the brick struck the nail.

Hence, the heat produced is H = Ep = 21.56 J

The heat produced in the system when the brick hits the brick, H = 21.56 J