Question

An artificial satellite is moving in a circular orbit around the Earth. Which statement is correct?

Options

• A force is needed to keep it moving as its speed is changing.

• No force is needed as it is in space.

• A tangential force of gravity increases its speed.

• Centripetal force due to the Earth’s gravity continuously changes the direction of velocity.

Answer 1

Centripetal force due to the Earth’s gravity continuously changes the direction of velocity.

Explanation:

An artificial satellite moves in a circular orbit because Earth’s gravitational force acts as the centripetal force. This force acts towards the centre of the earth and continuously changes the direction of the satellite’s velocity without changing its speed in a circular orbit.