Home
Back
Kinetic Energy Formula:
| From: | To: |
Kinetic energy is the energy possessed by an object due to its motion. It is a scalar quantity that depends on both the mass and velocity of the object, but can also be calculated from momentum using the relationship between these physical quantities.
The calculator uses the kinetic energy formula derived from momentum:
Where:
Explanation: This formula shows that kinetic energy is proportional to the square of momentum and inversely proportional to mass, allowing calculation of energy without knowing velocity directly.
Details: Calculating kinetic energy from momentum is particularly useful in physics problems where momentum is known or more easily measured than velocity, and in conservation of energy and momentum scenarios.
Tips: Enter momentum in kg m/s and mass in kg. Both values must be positive numbers. The result will be displayed in Joules (J).
Q1: Why calculate kinetic energy from momentum instead of velocity?
A: In many physics problems, particularly those involving collisions and conservation laws, momentum is conserved and more readily available than velocity.
Q2: What are the units for kinetic energy?
A: Kinetic energy is measured in Joules (J) in the SI system, where 1 J = 1 kg·m²/s².
Q3: Can this formula be used for relativistic speeds?
A: No, this formula is for classical (non-relativistic) mechanics. For objects moving at significant fractions of light speed, relativistic equations must be used.
Q4: How is this formula derived?
A: The formula is derived by substituting v = p/m into the classical kinetic energy formula KE = ½mv² and simplifying.
Q5: What are typical kinetic energy values?
A: Kinetic energy values vary widely from microscopic scales (10⁻¹⁹ J for atoms) to macroscopic scales (thousands of Joules for moving vehicles).