When angle between them is zero
A group of protons and neutrons surrounded by electrons
Answer:
Your answer is D It does not need to be repeatable.
the reason for this is because C is correct.
You need to be able to experiment on something multiple times so that you can gather further data to imbedded your evidence in facts.
Let the data is as following
mass of payload = "m"
mass of Moon = "M"
now we know that we place the payload from the position on the surface of moon to the position of 5r from the surface
So in this case we can say that change in the gravitational potential energy is equal to the work done to move the mass from one position to other
so it is given by

we know that


now from above formula


so above is the work done to move the mass from surface to given altitude