Orbital Speed + Radius + Period

What is orbital speed?

The speed of an object moving along its orbit.

What is orbital radius?

The distance from the centre of the orbit to the orbiting object in a circular orbit.

What is orbital period?

The time taken to complete one orbit.

What happens to orbital speed when the radius of a circular orbit around the same central mass increases?

Orbital speed decreases.

What happens to orbital speed when the radius of a circular orbit around the same central mass decreases?

Orbital speed increases.

Why do satellites in lower circular orbits travel faster?

A stronger gravitational field requires greater orbital speed to maintain the smaller orbit.

Why do satellites in higher circular orbits travel more slowly?

The gravitational attraction is weaker at greater distances, so a lower orbital speed is needed.

What happens to orbital period as orbital radius increases for circular orbits around the same central mass?

The orbital period increases.

Why does a satellite in a higher orbit take longer to complete an orbit?

It travels around a larger path at a lower orbital speed.

What happens to the orbital period when orbital radius decreases?

The orbital period generally decreases.

Why is the speed of a planet not constant throughout an elliptical orbit?

Its speed changes as its distance from the star changes.

When does a planet in an elliptical orbit travel fastest?

When it is closest to the star.

When does a planet in an elliptical orbit travel slowest?

When it is furthest from the star.

Why does a planet speed up as it approaches the Sun?

Gravitational potential energy is transferred into kinetic energy.

Why does a planet slow down as it moves away from the Sun?

Kinetic energy is transferred into gravitational potential energy.

What happens to a satellite's velocity even when its orbital speed is constant?

Its direction changes continuously.

Why is an orbiting satellite accelerating despite having constant speed?

Its velocity changes direction.

Does a satellite need a continuous engine thrust to remain in a stable orbit?

No, gravity maintains the orbit without continuous thrust.

What happens when the speed of a satellite changes?

Its orbital path may change, depending on the direction and size of the speed change.

Why does the central mass affect orbital speed?

A more massive central object produces a stronger gravitational field at the same distance.