Question

What is the magnitude of the gravitational force between the Earth and a 1kg object on its surface ? (Mass of the earth is `6xx10^(24)` kg and radius of the Earth is `6.4xx10^(6) m)`.

Answer 1

Correct Answer - 9.8 N
Given that ,
Mass of the body ,`m=1 kg`
Mass of earth `m=6xx10^(24) kg`
Radius of the Earth , `R=6.4xx10^(6)` m
Now , magnitude of the gravitational force (F) bettween the earth and the body can be calculated
`F=G(Mm)/(r^(2))=6.67xx10^(-11)(6xx10^(24)xx1)/((6.4xx10^(6)^(2))`
`(6.67xx6xx10^(13)xx1)/((6.4xx6.4xx10^(12)))=(6.67xx6xx10)/((6.4xx6.4))=9.7 N ` (approx.)