Question

A student pushes against a tree with a force of 10 newtons the tree does not move. What is the amount of force exerted by the tree on the student

Answer 1

Newton's third law:

For every action, there is an equal and opposite reaction.

The student pushes against the tree with a force of 10 Newtons, therefore the tree pushes back with an equal magnitude of force, 10 Newtons.