A 0.5kg hammer hits the head of a nail with a force of 25N. What is the force the head of the nail is doing on the hammer?

25N

Explanation:

The force the head of the nail is doing on the hammer is 25N. This is based on the newton's third of law of motion.

It states that "action and reaction are equal but opposite in direction".

A body exerting a force of 25N on another will get a reaction force of an equal but negative magnitude of force in the opposite direction.

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).