In normal conditions, kinetic energy can be easily calculated when you have the values of mass and velocity. With these values, the KineticEnergyCalculator will allow you to simply and quickly calculate kinetic energy. However, what will you do if you do not know the value of velocity? Or the conditions demand that you not determine the value of velocity to calculate kinetic energy. You might feel stuck. Fortunately, Physics is fascinating and you have several options to calculate kinetic energy without velocity.
The easiest and most common way to calculate kinetic energy without velocity is to use potential energy (P.E.) within a closed system. In closed systems with conserved energy, K.E. is the lost P.E. of any object. A case in point would be the gravitational potential energy of a body converted into K.E. when the body falls under gravity. Its gravitational P.E. will be converted into K.E.
For a falling body,
P.E. = mgh
Where,
m is the mass
g is the gravitational acceleration and
h is the height from which the body starts falling.
So, the potential energy will be equal to the kinetic energy when the body touches the ground or just before touching the ground. It is how you can indirectly know what the K.E. of the body is without knowing its velocity.
Other methods of determining kinetic energy without velocity may include the use of rotational motion, the conservation of momentum, and the work-energy principle.