Potential Energy of an Object at a Height

Q.

Derive the expression for gravitational potential energy.$Ep=mgh$

Q.

How does an object gain potential energy?

Q. Earth receives light even during a cloudy day. This is because clouds are:

1. Luminous
2. Transparent
3. Translucent
4. Opaque

Q. Name two natural sources of light.​

Q. It is difficult to climb the steps having greater inclination. Why?

1. Less erect steps require less energy
2. None of the above
3. Greater inclination requires less effort because of the high mechanical advantage
4. Greater inclination requires more effort because of the low mechanical advantage