Body of mass m is taken from the earth's surface to the height equal to twice the radius (R) of the earth. The change in potential energy of body will be :

Question

Body of mass m is taken from the earth's surface to the height equal to twice the radius (R) of the earth. The change in potential energy of body will be : (A)  (1/3) mgR (B)  2 mgR (C)  (2/3) mgR (D)  3 mgR

Tardigrade Admin · Accepted Answer

Change in PE = - (GMm/3R) - (- (GMm/R) ) = (2/3) (GMm/R) = (2/3) mg R

Q. Body of mass $m$ is taken from the earth's surface to the height equal to twice the radius $(R)$ of the earth. The change in potential energy of body will be :

$\frac{1}{3} m g R$

$2 m g R$

$\frac{2}{3} m g R$

$3 m g R$

Change in PE = $- \frac{GM m}{3 R} - (- \frac{GM m}{R})$
$= \frac{2}{3} \frac{GM m}{R} = \frac{2}{3} m g R$

Q. Body of mass m is taken from the earth's surface to the height equal to twice the radius (R) of the earth. The change in potential energy of body will be :

31​mgR

2mgR

32​mgR

3mgR