A person stands on the surface of the Farth. The mass of the...

A person stands on the surface of the Farth. The mass of the person is $m$ and the mass of the Earth is $M$. The person jumps upward, reaching a maximum height $h$ above the Earth. When the person is at this height $h,$ the magnitude of the force exerted on the Earth by the person is a) $m \mathrm{~g}$. c) $M^{2} g / m$ e) zero. b) $\mathrm{Mg}$ d) $m^{2} g / M$.

A person stands on the surface of the Farth. The mass of the person is $m$ and the mass of the Earth is $M$. The person jumps upward, reaching a maximum height $h$ above the Earth. When the person is at this height $h,$ the magnitude of the force exerted on the Earth by the person is
a) $m \mathrm{~g}$.
c) $M^{2} g / m$
e) zero.
b) $\mathrm{Mg}$
d) $m^{2} g / M$.

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Gravitational Force

Gravitational force is the attractive force between two masses, described by Newton’s law of universal gravitation. Near a planet’s surface, this force is typically approximated as the product of the mass and the acceleration due to gravity (mg). This concept is used to determine the weight of an object under the influence of a planet’s gravity.

Newton's Third Law of Motion

Newton's Third Law states that for every action there is an equal and opposite reaction. In the context of gravitational interactions, this means that the force exerted by a mass (such as a person) on the Earth will be equal in magnitude and opposite in direction to the force exerted by the Earth on that mass, regardless of their relative sizes.

Projectile Motion and Free Fall

During projectile motion, even at the maximum height where the upward velocity momentarily becomes zero, the object is still subject to the force of gravity, meaning it is in free fall. The fact that the velocity is zero at that moment does not imply that the gravitational force has vanished, as acceleration due to gravity continues to act on the object.

Transcript

Please give Ace some feedback