On a surface of a planet of radius R and mass M the acceleration due to gravity is 7m/s?. Consider another planet of radius 2R and mass 0.4M. What would the acceleration due to gravity be on this new planet? Show your calculations.

0.7 m/

Explanation:

From Newton's law of universal gravitation,

F =

and from Newton's second law of motion,

F = mg

So that;

mg =

⇒ g =

For the first planet,

7 =

⇒ G = .............. 1

For the second planet,

g =

   =

⇒ G = ............. 2

Equating 1 and 2, we have;

=

g =

  =

  =

g = 0.7

Therefore, the acceleration due to gravity on the new planet is 0.7 m/.

i think it's 35 meters