Question

Why a runner falls in the forward direction, if his foot is tripped by a stone.

Answer 1

Answer:According To Newton's Third law of Motion:

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

Action=-Reaction

-->So when the runner pushes the ground[action force] he experiences an equal and opposite reaction force from the ground which he utilizes to run faster.

--->The harder he pushes the ground, more reaction force he gets which helps him to move forward.