The earth’s gravitational pull is a downward force, pulling objects towards the centre of the earth. The gravitational pull on objects depends on three things:
1. The mass of the object.
2. The mass of the earth.
3. The distance between the centres of the objects and the earth.
Effects of Gravitational Pull:
1. Work is Done against Gravity in Lifting an Object from the Earth: Work is done every time we lift an object from the earth. Lifting an object from the ground involves opposing gravitational pull. An aeroplane must spend a lot of energyEnergy is the ability to do work. Energy exists in several forms such as heat, kinetic or mechanical energy, light, potential energy, and electrical energy. Units of Energy: The SI unit of energy is the joule (J) or newton-meter (N * m). The joule is also the SI unit of work. to lift itself from the ground.
2. Revolution of the Moon around the Earth: The moon is kept in orbit around the earth due to gravitational attraction. If not for the gravitational pull, the moon will move away from the sun.
3. Balance of Planets in our Solar System: The Earth and all the planets in our solar system exercise gravitational pulls on one another and mutually balance each other in space. This is what keeps the solar system in place.
4. Stability on Earth: The earth is a sphere, but gravity keeps us stable and upright whenever we are on the surface of the earth.
5. Weight: Everybody has weight, the weight of an individual is a measure of the gravitational pull of the earth on that person. The bigger the person is, the bigger the weight the person has.