Question

An artificial satellite remains in orbit and does not fall on to the Earth because

• A. the centrifugal force acting on it balances the gravitational attraction
• B. the on-board rocket motors provide continuous boost to keep it in orbit
• C. its transverse velocity keeps it from hitting Earth although it falls continuously
• D. due to its high speed it derives sufficient lift from the rarefied atmosphere

Hint:

Orbital motion is a balance of gravity and forward velocity — a continuous free-fall.

Answer 1

The Correct Option is C

An artificial satellite remains in orbit and does not fall onto the Earth primarily because its transverse velocity keeps it from hitting Earth although it falls continuously. Here's how this works:

1. Gravitational Force: The satellite is constantly acted upon by Earth's gravitational force, which pulls it towards the planet.

2. Centripetal Force: To maintain its orbit, the satellite needs a centripetal force that allows it to move in a circular path. Gravity acts as this centripetal force.

3. Transverse Velocity: The satellite is launched into orbit with a high transverse velocity (perpendicular to the force of gravity). This speed ensures that as it falls towards Earth, its curved path due to gravity matches the curvature of the Earth, thus keeping it in orbit.

4. Continuous Free Fall: The satellite is in continuous free fall towards Earth. However, its forward motion ensures that it falls around the Earth rather than directly onto it.

This delicate balance of forces and velocity means that the satellite orbits Earth, appearing to float while actually being in constant motion.