Question

A satellite orbits the Earth. The name of the force that keeps the satellite in orbit is:

a. tension
b. gravity
c. friction
d. normal

Answer 1

b. gravity. Gravity is the force responsible for keeping a satellite in orbit around the Earth. Newton's law of gravitation,
`\( F = \frac{{G \cdot m_1 \cdot m_2}}{{r^2}} \)`, describes the gravitational force that acts as a centripetal force, maintaining the satellite's circular motion. Understanding this gravitational interaction is crucial for comprehending orbital dynamics.

Step-by-step explanation:

Gravity is the force that keeps a satellite in orbit around the Earth. This force is responsible for the attractive pull between two masses, in this case, the Earth and the satellite. The gravitational force acts as a centripetal force, continuously pulling the satellite towards the center of the Earth, preventing it from flying off into space.

The gravitational force between two objects is given by Newton's law of gravitation, expressed as
`\( F = \frac{{G \cdot m_1 \cdot m_2}}{{r^2}} \)`, where:

- ( F ) is the gravitational force,

- ( G ) is the gravitational constant,

-
`( m_1 )` and
`\( m_2 \)` are the masses of the two objects, and

- ( r ) is the distance between the centers of the two masses.

In the context of a satellite orbiting Earth,
`\( m_1 \)` is the mass of the Earth,
`\( m_2 \)` is the mass of the satellite, and
`\( r \)` is the distance between the center of the Earth and the satellite. The gravitational force is crucial for maintaining the circular motion of the satellite around the Earth, balancing the inertial tendency of the satellite to move in a straight line with the gravitational pull towards the Earth's center.

Understanding the interplay between gravitational force and centripetal force is fundamental in comprehending the dynamics of objects in orbit around a massive body. In the absence of gravity, satellites would not stay in orbit, and they would follow a straight-line path tangentially to the Earth's surface.

Answer 2

Gravity is the force that maintains a satellite in orbit around Earth, providing the centripetal acceleration needed for circular motion. The answer is option b.

Step-by-step explanation:

The force that keeps a satellite in orbit around the Earth is gravity. This force provides the necessary centripetal acceleration that allows the satellite to move in a circular path around the Earth. It’s important to note that while the gravitational force keeps the satellite in orbit, this is not a one-sided interaction. According to Newton's Third Law, the Earth exerts a gravitational force on the satellite, and the satellite exerts an equal and opposite force on the Earth.

Hence, the answer is option b.