Energy
In simple terms, energy is the ability to do some work. Work such as lifting a glass of water or holding a cricket bat. It is the capacity to do work. Its unit is measured in a term called joules. There are many sorts of energy. Some main kinds are kinetic, nuclear, thermal, and electrical.
Kinetic energy
It is the type of energy an object possesses when in motion. Suppose a car is moving. It has kinetic energy. Any moving object possesses kinetic energy. A cricket ball moving in the air contains kinetic energy.
There is a very important equation that all students must learn. Using this equation, the kinetic energy of any moving body can be found. Kinetic energy = ½ mv2 (½ x m x v squared) . Mass is denoted by m, and velocity is denoted by v.
Let’s do some mathematics relating to kinetic energy.
Suppose a ball is moving with a velocity of 6 m/s and its mass is 2 kilograms. What is the kinetic energy it possesses? Putting the values into the equation, KE = ½ x 2 x 62 = 36 joules.
Suppose a knife is moving with a velocity of 5 m/s and its mass is 1 kilogram. What is the kinetic energy it possesses? Putting the values into the equation, KE = ½ x 1 x 52 = 12.5 joules
Suppose a plane is moving with a velocity of 100 m/s, and its mass is 2000 kilograms. What is the kinetic energy it possesses? Putting the values into the equation, KE = ½ x 2000 x 1002 = 100000000 joules.
Suppose a boy is moving with a velocity of 9 m/s, and his mass is 60 kilograms. What is the kinetic energy it possesses? Putting the values into the equation, KE = ½ x 60 x 92 = 2430 joules.
