A hammer exerts an average force of 1200 N on a nail. If the nail penetrates 0.05 m into the wood, how much heat energy is generated?

The average force applied to the nail is $F = 1200 \text{ N}$.
The distance the nail penetrates is $d = 0.05 \text{ m}$.

The work done by the force is converted into heat energy due to friction and deformation as the nail penetrates the wood. The formula for work done is:

Substitute the given values:

Assuming all the work done is converted into heat energy, the heat energy generated is equal to the work done.

The heat energy generated is $60 \text{ J}$.