Question

Which best describes Sid’s error?

Tangential speed changes throughout a satellite’s orbit.
Centripetal force is perpendicular to the velocity of the satellite.
Tangential speed increases with a satellite’s increasing distance from Earth.
Centripetal force can sometimes slow down a satellite in orbit.

Answer 1

Explanation :

First considering Sid's statements, the description of tangential speed and centripetal acceleration are correct.

But for Centripetal force, the description is incorrect because centripetal force is always perpendicular to the velocity.

Sid's error can be corrected by the statement (b) i.e. "Centripetal force is perpendicular to the velocity of the satellite".

Answer 2

Centripetal force is perpendicular to the velocity of the satellite.

Step-by-step explanation:

Centripetal force acts when a body is in circular motion. It acts towards the center of the circular orbit along the radius. Tangential speed remains constant and acts along the tangent, perpendicular to the radius of the the circular orbit. The centripetal acceleration acts along the direction of the centripetal force i.e. along the radius.

Thus, tangential speed is perpendicular to the centripetal force.

Sid's error is that he has written that centripetal force acts parallel to the velocity of the satellite. The satellite revolving around the earth has constant tangential speed. The centripetal force is perpendicular to the velocity of the satellite and points towards the earth.