A body of mass 500g is town upwards with a velocity `20 ms^(-1)` and reaches back to the surface of a planet after 20s. Then the weight of the body on that planet is

Options

A. 2N
B. 4N
C. 5N
D. 1N

Answer

D

Explanation

Here , u = 20 m/s , m = 500 g = 0.5 kg , t = 20s
Using `h = ut + 1/2 "gt"^2`
Where g is the acceleration due to gravity on the plane
` 0 = 20 xx 20 + 1/2 (-g)(20)^2" or " g = 2m//s^2`
Weight of the body on the planet ` = mg = 0.5 kg xx 2 m//s^2 = 1N`