Question

Which statements accurately describe satellite motion? Check all that apply.

Gravity is the only force acting on a satellite.
Inertia is the only cause of a satellite’s circular motion.
Air resistance prevents satellites from staying in orbit for very long.
Circular orbits result from the interaction between gravity and inertia.
Gravity provides the centripetal force for satellites.
Satellites are in free fall around Earth or other central objects.

Answer 1

Correct statements: 4, 5, 6.

Brief notes on each:

- Gravity is the only force acting on a satellite. — False. Gravity is the dominant force, but other forces can act (atmospheric drag in low orbits, solar radiation pressure, magnetic torques, engine thrusts, etc.).

- Inertia is the only cause of a satellite’s circular motion. — False. "Inertia" (the tendency to move straight) by itself doesn’t produce circular motion; circular motion results from the tangential velocity (inertial motion) being continuously deflected by gravity.

- Air resistance prevents satellites from staying in orbit for very long. — False as stated. Atmospheric drag can cause orbital decay for low-Earth objects, but many satellites in higher orbits remain for years to decades; drag is not universally decisive.

- Circular orbits result from the interaction between gravity and inertia. — True. The tangential (inertial) motion and inward gravitational force together produce a circular orbit when balanced.

- Gravity provides the centripetal force for satellites. — True. Gravity supplies the inward force that keeps the satellite on its curved path.

- Satellites are in free fall around Earth or other central objects. — True. In orbit they are continuously falling toward the central body while moving fast enough tangentially to keep missing it, so they are in free fall (neglecting other forces).