Answer:
A) 2/9 g
Explanation:
Acceleration due to gravity (free fall acceleration) of the earth is given as:
g = GM/R² _________ (1)
Where G = gravitational constant
M = mass of earth
R = radius of earth
For the newly discovered planet having twice the mass of earth and thrice it's radius, free fall acceleration will be:
a = (G*2M)/(3R)²
a = 2MG/9R² ________ (2)
Making G subject of formula in (1),
G = R²g/M
Putting this into (2):
a = (2 * M * R² * g)/(9 * R² * M)
=> a = 2g/9
