Answer: acceleration due to gravity of planet a would be twice that of planet b. Given that the radius are thesame.
Step-by-step explanation:
Acceleration due to gravity is as a result of the gravitational force of attraction of a planet to its centre.
g = GM/r^2
Where;
g = acceleration due to gravity
G = gravitational constant
M = mass of planet
r = radius of planet
Given that the two planet have the same radius, if the mass of planet a is twice the mass of planet b the the acceleration due to gravity of planet a would be twice that of planet b, because acceleration due to gravity is directly proportional to the mass of the planet.