Acceleration due to gravity at height \(h\)
\(g'=\frac{g}{[1+\frac{h}{R}]^2}\)
So weight at given height
\(mg'=\frac{mg}{[1+\frac{h}{R}]^2}\)
=\(\frac{18}{[1+\frac{1}{2}]^2}=8N\)
\(\text{Therefore, the correct option is (D):} 8N\)
In mechanics, the universal force of attraction acting between all matter is known as Gravity, also called gravitation, . It is the weakest known force in nature.
According to Newton’s law of gravitation, “Every particle in the universe attracts every other particle with a force whose magnitude is,
On combining equations (1) and (2) we get,
F ∝ M1M2/r2
F = G × [M1M2]/r2 . . . . (7)
Or, f(r) = GM1M2/r2
The dimension formula of G is [M-1L3T-2].