Conservation of Momentum Calculator

Find the final velocity after a perfectly inelastic collision.

Final velocity (stuck together) 0.8

Formula: v = (m₁v₁ + m₂v₂) ÷ (m₁ + m₂)

Step-by-step with your numbers:
1. Values used:
2. Mass 1 = 2
3. Velocity 1 = 5
4. Mass 2 = 3
5. Velocity 2 = -2
6.
7. Final velocity (stuck together) = 0.8
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Total momentum is conserved in collisions. This finds the common velocity when objects stick together.

How the Math Works

The Conservation of Momentum Calculator applies the principle of momentum conservation in perfectly inelastic collisions, where two objects stick together after impact. The formula v = (m₁v₁ + m₂v₂) ÷ (m₁ + m₂) calculates the final velocity by summing the initial momenta (mass × velocity) of both objects and dividing by their combined mass. This ensures the total momentum before collision equals the total momentum after collision, as no external forces act on the system. The derivation assumes no energy loss to heat or deformation, focusing solely on momentum transfer between the two objects.

Practical Applications

To use the calculator, input the masses (m₁ and m₂) and initial velocities (v₁ and v₂) of the two colliding objects. For example, if a 1,000 kg car moving at 20 m/s collides with a stationary 1,500 kg truck, plug in v₁ = 20 m/s, v₂ = 0 m/s, m₁ = 1000 kg, and m₂ = 1500 kg. The calculator computes the final velocity of the combined system, which is critical in engineering and safety design to assess collision outcomes and minimize damage.

Day-to-Day Use

Understanding momentum conservation helps in everyday scenarios like vehicle safety design, where crumple zones and airbags are engineered to manage collision forces. It also applies to sports, such as football tackles or ball dynamics, where players or equipment interact with high momentum. Additionally, it aids in analyzing playground equipment (e.g., swings colliding with barriers) or even everyday activities like catching a moving object, where transferring momentum reduces injury by distributing force over time.

Worked example

2 kg at 5 m/s meets 3 kg at −2 m/s → final 0.8 m/s.

FAQ

Is energy conserved too?

No — inelastic collisions lose kinetic energy to heat and deformation.