How does height affects the potential energy of a body?

The higher the height above the more PE (Potential Energy), the body posses as seen in the formula PE = mass*gravity*height. m and g are constant hence only h affect PE

Explanation:

Potential Energy (PE) is the energy the body posses by virtue of its vertical height above the ground because, once the body is released, it will release or create some energy eg hydroelectricity power generation or a car going downhill does not need to be accelerated by the driver since it can roll over on its own due to PE

i think it would be 80 km/h because 30 + 50 = 80 (sorry if this not the right answer i'm trying my best)

f=ma newton's second law 7x8=56n