Question

calculate the acceleration due to gravity on the surface of planet whose mass and radius are the doubled that the mass and radius of the earth

Answer 1

the acceleration on planet earth is g=9.81 and you can find it using newton's gravity equation F=G*m1*m2*r^2

in this equation lets consider m1 is the mass of earth M. m2 is not even close to M so we re not gonna take it into consideration.

thus g=G*M/r^2

if u double the radius and the mass of the planet u get a new acceleration:

a= G*2M/(2r)^2

a= 2/4 * G*m/r^2 and since g*m/r^2= 9.81

a= 0.5 * 9.81

a=4.905

Answer 2

G
$g = \frac{Gm}{ {r}^{2} }$
where
••g is acceleration due to gravity
•• G is universal gravitational constant
••m is mass of that planet
••r is the radius of that planet

... From the above given answer in the picture we can see that the acceleration due to gravity on that planet is half of that of earth's.