Circular Orbits Flashcards

All 6 cards in this deck

What force keeps planets, moons and artificial satellites in their orbits?

Gravity (the gravitational force of attraction).

What is an artificial satellite?

A man-made object placed in orbit around a planet, e.g. the Hubble Space Telescope.

What is the difference between a planet and a moon?

Planets orbit the Sun; moons (natural satellites) orbit planets.

In a circular orbit, in which direction does the gravitational force on the orbiting body act?

Towards the centre of the orbit — towards the body it orbits.

For a body in a circular orbit, what happens to its velocity and its speed?

The velocity changes because the direction of motion keeps changing, but the speed stays constant.

True or false? A satellite moving in a circular orbit at constant speed is accelerating.

True. Gravity makes it accelerate towards the planet, changing its direction and so its velocity.