Question

The gravitational force of the Earth pulls down on a stone after someone tosses it off a cliff According to Newton's third law, what is the equal but opposite force in this interaction?
a.there is no equal and opposite force in this case


b.the force of the stone pushing down on the air


c.the force of the stone's gravity pulling up on the Earth


d.the force of air resistance pushing up on the stone


e.The force the stone exerts on the persons hand

Answer 1

Answer:

The correct answer is c.) the force of the stone's gravity pulling up on Earth.

Explanation:

The correct answer is c.) the force of the stone's gravity pulling up on Earth.

The Earth's size is much greater than size of the stone.

From Newton's Third Law that the force with the Earth attracts the stone is the same as the force of gravitational attraction that the stone exerts on Earth.

Let $m_1$ be the mass of Earth and $m_2$ be the mass of the stone.

Therefore F = $m_1 \times a_1$ = $m_2 \times a_2$  where it is known that $m_1 >> m_2$ which implies that $a_2 >> a_1$.

The acceleration of the stone towards the Earth is much greater than the acceleration of the Earth towards the stone, and so the stone falling towards the Earth is actually visible and perceptible.