The gravitational potential energy U is defined as the product of mass m, the acceleration of gravity g and the height of object h.

We do not have the mass of the hiker. But we know that its W weight is:

Where

So:
.
So:

J
The hiker has gained 30,000 J of energy
For the answer to the question above, the answer is simple.<span> among</span> the choices given the only way on not to conserve energy is by using the available fossil fuel.
I hope my answer helped you. feel free to ask more questions. Have a nice day!
Answer:
You can get w =Fxd 20Nx5m w=100N energy= w÷t 100N÷4s E=25J 3 you can apply 3J in one second
A) average acceleration = final velocity - initial velocity / time
= 7700 - 0 / 11
= 700ms^-2
B) force = mass x acceleration
= (3.05 x 105) x 700
= 320.25 x 700
= 224,175N