Energy and Work – an Overview
In physics and engineering we use knowledge of a quantity called energy to understand nature and to design efficient machines and improve chemical processes.
There are many different forms of energy. Some examples include the kinetic energy of a moving object, the chemical energy released when a fuel burns, and the thermal energy due to an object’s temperature. Work is the process that takes place when energy is transferred. We see this when an object moves under the action of a force. The force does work as it moves the object.
An amazing thing about energy is that it cannot be created or destroyed. It can be converted into different types of energy. There will always be the same amount of energy before an event takes place and after the event takes place. It is a fact which is referred to as the conservation of energy.
Just think about that for a moment. What this law tells us is that if we calculate the total energy before we do something, for example drop an apple to the ground, and then calculate the total energy just before the apple hits the ground, then we will calculate the exact same amount of energy.
In my video above on Energy and Work I explain that we may use the conservation of energy to do very cool calculations. The example I give is to calculate the velocity of an apple just before it hits the ground.