Question

The centripetal force on a satellite revolving around the Earth is $F$. The gravitational force of the Earth is also $F$. What will be the net force on satellite?

Answer 1

Centripetal force:

1. It is the force that is required to keep an object moving along a curved path.
2. It is always directed inwards towards the center of the orbit of the rotating object.
3. Mathematically, the centripetal force acting on an object (satellite revolving around Earth) is given by $\frac{m{v}^2}{R}$, where $m$ is a mass of an object, $v$ is the velocity of the object and $R$ is the radius of the orbit.

Gravitational force:

1. Gravitational force is the force of attraction between two bodies which is directly proportional to the product of masses of the bodies and inversely proportional to the square of the distance between them.
2. The gravitational force acting on the satellite will be $G\frac{Mm}{R^2}$, where $G$ is the gravitational constant, $M$ is mass of Earth, $m$ is mass of satellite and $R$ is the distance between Earth and satellite.

Net force acting on satellite:

1. For a satellite to keep revolving around Earth a centripetal force is required.
2. This required centripetal force is supplied by the gravitational force.
3. Thus, the centripetal force and gravitational force are the same.
4. So, there is only one force $\left(F\right)$ acting on the satellite.
5. Therefore, the net force of the satellite is equal to $F$.

Hence, the net force of the satellite is equal to $F$.