Kinetic Energy:
Kinetic Energy is defined as the work needed to accelerate a body of a given mass from rest to
its current velocity.
Kinetic Energy Formula :
Kinetic Energy: E_{k} = ½ mv^{2}
Mass: m = E_{k} / ½ v^{2}
Velocity:
where,
E_{k} = Kinetic Energy,
M = Mass of object,
V = Velocity or Speed of object,
Kinetic Energy Example:
Case 1: Determine the Kinetic energy of a 500kg roller coaster train which moves at a speed of 20 m/s.
M = 500 kg, V = 20 m/s
Step 1: Substitute the values in the below kinectic energy formula:
Kinetic Energy: E_{k} = ½ mv^{2}
= ½ x 500 x 20^{2}
= 0.5 x 500 x 400
Kinetic Energy: E_{k} = 100000 Joules or 1 x 10^{5} Joules
This example will guide you to calculate the kinetic energy manually.
Case 2: What is the speed of a 55 kg woman running with a kinetic energy of 412.7 J?
E_{k} = 412.7, M = 55 kg
Step 1: Substitute the values in the below Velocity formula:
This example will guide you to calculate the velocity manually.

