If the mass and radius of a planet are twice the mass and radius of the earth respectively, what would be the value of gravitational acceleration the surface of that planet?

Options

A. `9.8ms^(-2)`
B. `19.6ms^(-2)`
C. `4.9ms^(-2)`
D. `2.45ms^(-2)`

Answer

C

Explanation

Gravitational acceleration on surface of earth `g =G M e/R_e^2=9.8ms^(-2)`
Now, putting `M =2M_c and R =2R_e" for the planet, "`
`g.=(G(2M_c))/(2R_c)^(2)`
`=1/2 ((GM_c)/R_c^2)=1/2 xx9.8 =4.9,s^(-2)`