What is Kinetic energy

What is Kinetic energy
3.6 (72.53%) 554 votes

kinetic energy

This is the energy of motion.
There are many forms of kinetic energy – vibrational (the energy due to vibrational motion), rotational (the energy due to rotational motion), and translational (the energy due to motion from one location to another).
Kinetic energy expresses the fact that a moving object can do work on anything it hits. The total mechanical energy of an object is the sum of its kinetic energy and potential energy.

If the object is moving the kinetic energy equals one half times the mass (m) of the object times (t) the square of the speed (v) of the object:



m – the mass of the object is measured in kg. If the mass is in gramms for example you have to calculate it in kg to use it properly in the formula.

v – velocity of the object is measured in m/s (meters per second)

The answer should always be stated in joules (J), which is the standard unit of measurement for kinetic energy.

1 J is equivalent to 1 kg * m2/s2.


The velocity of the object (if you do not know it) can be calculated if we know the distance and time of traveling of the object using the equations:

v = d / t,



d – distance, measured in meters (m)

t – time, measured in seconds (s)

kinetic energy concept

Do you know why if you bike and try to stop suddenly it’s not possible and it will take a few seconds to stop completely? Do you know why it’s dangerous to step out suddenly on the road and why the car cannot stop immediately? This is because of the kinetic energy.
Look at the equation above. The kinetic energy depends of the mass and spped of the objective (car). Therefore of a truck and car are driving with one and the same speed the truck needs more time and distance to stop, because the truck is more heavy than the car. The same truck can do more work on you than the car.
Kinetic energy – examples:
Kinetic energy of  moving truck
truck kinetic energy moving truck
Speed and stopping distance (see more at shofior.com).
Kinetic energy of sledding