A body of mass 10 kg is dropped from a height of 10 m on a planet, whose mass and radius are double that of the Earth. Find the maximum kinetic energy the body can possess.
`("Take" g_(E) = 10 ms^(-2))`

Explanation

(i) (1.)Find the acceleration due to gravity on the planet, `g_(p)` by using the formula, `g_(p) = (GM_(p))/(R_(p)^(2))`
(2.) But, `M_(p) = 2 M_(E) "and" R_(p) = 2R_(E)`
Here, `g_(E) = (GM_(E))/(R_(E)^(2))`
Divide (1) by (2) and find the value of `'g_(p)'`.
Then, velocity at the surface, `v_(max) = sqrt(2g_(p)h)`. Then, maximum kinetic energy of the body is given by, `KE_(max) = (1)/(2)Mv_(max)^(2)`
(ii) 500 J