Question

according to newtons third law of motion, if a person in a canoe on a calm lake throws a heavy stone into the water in front of her, what happens to the canoe?
the canoe remains still because it is too heavy.
the canoe moves backward a bit.
the canoe moves forward and keeps going.
the canoe moves forward a bit.

Explanation:

Newton's Third Law of Motion states that for every action, there is an equal and opposite reaction. When the person throws the stone forward (action), the canoe experiences a backward force (reaction). The canoe's mass is not too great to prevent this small - scale motion as there is no continuous force to keep it moving forward (unlike if there was a continuous propulsion).

Answer:

The canoe moves backward a bit.