Ideal for AP Physics 1, AP Chemistry, SAT Math, and introductory college STEM courses.

    Elastic Collision Calculator

    Calculate final velocities for elastic and inelastic collisions between two objects

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    System Configuration

    Enter masses and initial velocities for collision calculation

    Derivation Steps

    v₁' = -3.00 m/s, v₂' = 5.00 m/s
    Elastic collision between mass 1 kg (velocity 5 m/s) and mass 1 kg (velocity -3 m/s)
    Conservation of momentum: m₁v₁ + m₂v₂ = m₁v₁' + m₂v₂'
    Conservation of kinetic energy: (1/2)m₁v₁² + (1/2)m₂v₂² = (1/2)m₁v₁'² + (1/2)m₂v₂'²
    Final velocity of mass 1: v₁' = 0 × 5 + 1 × -3 = -3.00 m/s
    Final velocity of mass 2: v₂' = 1 × 5 + 0 × -3 = 5.00 m/s
    Initial momentum: 2.00 kg·m/sKinetic Energy Conserved

    Real-Time Simulation

    Interactive visual 1D collision track and vector monitors

    m₁1.0 kgv₁: 5.0 m/sm₂1.0 kgv₂: -3.0 m/s
    Speed1.0x

    Kinematic Laws

    Momentum Conservation

    Momentum is conserved in all collisions (m₁v₁i + m₂v₂i = m₁v₁f + m₂v₂f).

    Kinetic Energy

    Kinetic energy is conserved only in **elastic** collisions, where objects rebound without permanent shape modifications or thermal/acoustic energy dissipation.

    Collision Formulas

    Elastic Collision (1D)

    v1f = ((m1 - m2) / (m1 + m2)) * v1i + ((2 * m2) / (m1 + m2)) * v2i
    v2f = ((2 * m1) / (m1 + m2)) * v1i + ((m2 - m1) / (m1 + m2)) * v2i

    Inelastic Collision (1D)

    vf = (m1 * v1i + m2 * v2i) / (m1 + m2)

    Elastic Collision

    Both momentum and kinetic energy are conserved. Objects bounce apart clean.

    Inelastic Collision

    Momentum conserved, energy partially lost to sound, heat, or internal deformation.

    Perfectly Inelastic

    Objects stick completely together after impact, traveling with a single unified final speed.

    Collision Calculator – Calculate Final Velocities in Elastic and Inelastic Collisions

    Collisions are fundamental to understanding momentum and energy conservation in physics. Our Collision Calculator helps you compute the final velocities of two objects after elastic or inelastic collisions, providing insights into conservation laws and real-world applications.

    🔹 What are Elastic and Inelastic Collisions?

    A collision occurs when two objects interact briefly, exchanging momentum and possibly energy.

    Elastic Collision: Both momentum and kinetic energy are conserved. No energy is lost to heat, sound, or deformation. Objects bounce off each other.

    Inelastic Collision: Momentum is conserved, but kinetic energy is not. Some energy is converted to other forms like heat or sound. Objects may stick together in perfectly inelastic collisions.

    Most real-world collisions are inelastic, while elastic collisions are ideal for atomic or subatomic interactions.

    🔹 Example Calculations

    Example 1: Elastic Collision - Equal Masses

    Mass 1 = 1 kg, Velocity 1 = 5 m/s

    Mass 2 = 1 kg, Velocity 2 = -3 m/s

    v₁f = ((1-1)/(1+1))*5 + ((2*1)/(1+1))*(-3) = 0 + 1*(-3) = -3 m/s
    v₂f = ((2*1)/(1+1))*5 + ((1-1)/(1+1))*(-3) = 1*5 + 0*(-3) = 5 m/s

    👉 Velocities are exchanged: Object 1 ends at -3 m/s, Object 2 at 5 m/s.

    Example 2: Inelastic Collision - Stationary Target

    Mass 1 = 2 kg, Velocity 1 = 4 m/s

    Mass 2 = 3 kg, Velocity 2 = 0 m/s

    v_f = (2*4 + 3*0) / (2 + 3) = 8 / 5 = 1.6 m/s

    👉 Combined velocity = 1.6 m/s

    🔹 Applications of Collision Physics

    • 🚗 Automotive Safety – Designing crumple zones and airbags
    • ⚽ Sports Science – Understanding ball trajectories and impacts
    • 🔬 Particle Physics – Analyzing subatomic collisions
    • 🏗️ Engineering – Structural impact analysis
    • 🎮 Game Physics – Realistic simulations in video games

    Academic & Scientific References

    For further understanding and validation of the formulas used above, we recommend exploring these authoritative resources: