Which physical quantity has a unit electron volt ($\mathrm{eV}$)?

Which physical quantity has a unit kilo-watt hour $\left(\mathrm{kWh}\right)$?

Is energy a scalar or a vector quantity? Why?

Define kinetic energy.

What is mechanical energy?

Name the kind of energy stored in a stretched bow.

When the height of an object is increased, what happens to its potential energy?

State the law of conservation of energy.