The Moon contains a little over 1 per cent of the mass of the Earth, yet without it, life would not have evolved as it has here on Earth.Without the tides, which are due to the Moon’s gravitational pull on the Earth, there would not have been the movement of the basic compounds required for the formation of early life.
Fig 3.4: Illustration of Solar System
SAMPLE PROBLEM 3F
Calculate the gravitational force on the Earth due to the Sun.Take G 6.7 1011 N m2 kg2, mass of Earth 6 1024 kg, mass of Sun 2.0 1030 kg, radius of the Earth’s orbit around Sun 1.5 1011 m.
SAMPLE ANSWER 3F The gravitational force on the Earth due to the Sun is 3.57 1022 N.
F Gm1m2 d2
(6.7 1011)(2 1030)(6 1024) (1.5 1011)2
3.57 1022 N
SCIENCE,TECHNOLOGY & SOCIETY
Presence of atmosphere The Earth’s atmosphere is a layer of gases which are held in place by the Earth’s gravity. A planet needs to be of sufficient mass in order to have enough gravity to keep an atmosphere.The Moon, along with many planets, is too small to hold an atmosphere.
