Force, Work and Energy
Renewable sources of energy are those that are renewed naturally. For example, solar energy, wind energy and water energy.
- Force is the push or pull of an object.
- By applying force, we can
-move a body,
-stop a moving body,
-change the direction of a moving body and
-make the body move slower or faster.
- Friction is the force which stops the movement of a body when the body is in contact with a surface.
- Force moves objects and friction stops objects.
- There are different types of forces. Animals and human beings use muscular force.
- The force applied with the help of tools is called mechanical force and it produces movement.
- The force of the earth on all the bodies present on it is called gravitational force.
- When a force moves an object through a distance, then work is said to be done.
- The tools which help us in doing work are called simple machines.
e.g., scissors, pulley, etc.
- Machines increase the speed of work being done and change the direction of force.
- Energy is the capacity to do work.
- The energy stored in our muscles is called muscular energy.
- A moving wind has energy. It is used to produce electricity.
- The energy possessed by moving water is called hydel energy or water energy.
- The electricity produced with hydel energy is called hydroelectricity.
- Burning of fuels produces heat energy. It is used to cook food, heating water and to run vehicles.
- Electrical energy is used to produce light and run different machines.
- The energy we get from the sun is called solar energy.
- Energy can be converted from one form to another.
- The sun is the ultimate source of energy.