1. What is energy? List the different forms of energy.
In physics, energy is a quantity that must be transferred on to the body to perform the work or any task as energy is defined via work.
There are two main forms of energy, namely, Potential energy (P.E), and Kinetic energy (K.E.). The energy is further classified into two types, namely renewable and non-renewable energy. Other forms of energy are:
2. What do you mean by the law of conservation of energy?
The law of conservation of energy states that the energy can never be created or destroyed but can be transformed into another form.
For example, when a box slides through a slop, at rest it has potential energy stored in itself when comes into motion that energy gets changed into the kinetic energy. The friction acts in the opposite direction. Therefore, the kinetic energy from the box gets transformed into the thermal energy heats the box and the slope.
3. How is power related to work and energy?
Work is done by energy and the rate at which any task is done is called the power. Let’s take an example, suppose you’re driving a car. The air friction is trying to slow down your car, the engine is powerful enough to accelerate the car. So here the work done is equal to the force applied by an engine to a distance. Now the rate at which the engine does this work is called the power.
4. Why do physical quantities need units?
The units are important because, without units, we can never express physical laws precisely just from qualitative reasoning. Such as I am 8 but if I say I am 8 years old so years old is the unit to define the quantity age.