Enter the total momentum (kg-m/s) and the mass (kg) into the calculator to determine the Kinetic Energy From Momentum. 

Momentum to Kinetic Energy Calculator

Enter any 2 values to calculate the missing variable

Kinetic Energy From Momentum Formula

The following equation is used to calculate the Kinetic Energy From Momentum. 

KE = p^2 / (2*m)

Variables:

  • Where KE is the Kinetic Energy From Momentum (Joules)
  • p is the total momentum (kg-m/s) 
  • m is the mass (kg) 

To calculate the kinetic energy from momentum, square the momentum, then divide by 2 times the mass.

Momentum to Kinetic Energy Conversion Table (Assuming Mass m = 1.00 kg)
Momentum (kg·m/s) Mass (kg) Kinetic Energy (J) Kinetic Energy (BTU)
0.51.000.1250.000118
11.000.5000.000474
1.51.001.1250.001066
21.002.0000.001896
2.51.003.1250.002962
31.004.5000.004265
41.008.0000.007583
51.0012.5000.011848
61.0018.0000.017061
7.51.0028.1250.026657
81.0032.0000.030330
101.0050.0000.047391
121.0072.0000.068243
151.00112.5000.106629
201.00200.0000.189563
251.00312.5000.296193
301.00450.0000.426518
401.00800.0000.758254
501.001250.0001.184771
601.001800.0001.706071
Assumes constant mass m = 1.00 kg. Relation: KE = p² / (2m). Energy conversion: 1 J ≈ 0.000947817 BTU (1 BTU ≈ 1055.06 J).

How to Calculate Kinetic Energy From Momentum?

The following two example problems outline the steps and information needed in order to calculate the Kinetic Energy From Momentum.

Example Problem #1:

  1. First, determine the total momentum (kg-m/s). In this example, the total momentum (kg-m/s) is measured to be 5.
  2. Next, determine the mass (kg). For this problem, the mass (kg) is calculated to be 3.
  3. Finally, calculate the Kinetic Energy From Momentum using the formula above: 

KE = p^2 / (2*m)

Inserting the values from above and solving the equation with the imputed values gives: 

KE = 5^2 / (2*3) = 4.166 (Joules)


FAQ

What is kinetic energy and how is it different from potential energy?

Kinetic energy is the energy that an object possesses due to its motion. It depends on the mass of the object and its velocity. Potential energy, on the other hand, is the stored energy in an object due to its position, shape, or state. While kinetic energy is associated with movement, potential energy relates to the potential of an object to move or change.

How does the conservation of momentum relate to kinetic energy?

The principle of conservation of momentum states that the total momentum of a closed system remains constant if no external forces are acting on it. In elastic collisions, both momentum and kinetic energy are conserved. However, in inelastic collisions, while momentum is conserved, kinetic energy is not because some of it is transformed into other forms of energy, such as heat or sound. The calculation of kinetic energy from momentum (KE = p^2 / (2*m)) is a direct application of these principles, showing how momentum can be used to determine the kinetic energy of a system.