Satellites and Gravity
A satellite is an objecct that orbits a planet in space. Satellites can be:
-natural, for example the moon.
-artificial- they have been put in space by humans.
A satellite is kept in orbit by a gravitational force. Gravity is a universal force of attraction between masses.Gravity keeps:
-planets orbitting the Sun
-the Moon orbitting the Earth
Centripetal force acts towards the centre of a circle; it keeps an object moving in a circle. Gravity provides the centripetal force that keep a satellite in orbit.
The weight of an object depends on the gravitational force on the surface of the planet.
Weight (N)= Mass (kg) x Gravitational field strength (N/kg)
w = m x g
On Earth, gravitational field strengt, g=10N/kg
The gravitational force between 2 objects gets weaker as the object are moved further apart. If distance is doubled, the force drops to 1/4. This is called the inverse square law.
Therefore, planets very close to the Sun experience a high gravitational force compared to plants that are further away.
The difference in gravitational force means that:
-planet closer to the Sun travel very quickly and have short…