Answer:
Part a)

Part b)

Step-by-step explanation:
As we know that the acceleration due to gravity is given as

where we know that
M = mass of planet
R = radius of planet
if we plug in mass of earth and radius of earth in above equation then we will have

now if we will find it for Venus


now from above formula again




Part b)
If Rock weigh 75 N on surface of Earth
then we have



now on the surface of Venus its weight is given as


