Question

A space traveller determines the radius of a planet to be half that of the earth. After landing on its surface, he
de the acceleration due to gravity to be twice of that of the surface of the earth. Find the ratio of the mass of planet​

Answer 1

Let the mass of planet is Mp

    radius of the planet is Rp

                            use Gravitational concept,

------------(1)

similarly, mass of the esrth is Me

radius of the earth is Re,

then, ------------------(2)

       now, according to question,

Rp = Re/2 and gp = 2ge, putting these values in equations (1) and (2), and divide equations (1) by (2)

  we get,  

hence, answer is 1 : 2

Answer 2

Answer:

The following pic might help ya!