The kinetic energy of an object is the extra energy which it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its current velocity. The kinetic energy of a single object is completely frame-dependent (relative). The kinetic energy of an object is directly proportional to the square of its speed. The kinetic energy equation is used frequently in conjunction with other forms of energy. Due to the law of conservation of energy, the total energy in a closed system will remain constant.
Kinetic energy is an expression of the fact that a moving object can do work on anything it hits; it quantifies the amount of work the object could do as a result of its motion. The total mechanical energy of an object is the sum of its kinetic Energy and potential energy. An object which has motion - whether it be vertical or horizontal motion - has kinetic energy.
FORMS OF KINETIC ENERGY:
There are many forms of kinetic energy.
Vibrational Energy: It is the energy due to Vibrational motion.
Rotational Energy: It is the energy due to rotational motion.
Translational Energy: It is the energy due to motion from one location to another.
Let us now see one solved example on how to calculate Kinetic Energy.
How much kinetic energy does an object have if its mass is 5.0 kg and it is moving at a speed of 4.0 m/s? EK = (1/2)mv2 EK = (1/2)(5.0 kg)(4.0 m/s)2 EK = 40 J
EK = (1/2)mv2
EK = (1/2)(5.0 kg)(4.0 m/s)2
EK = 40 J