gen-define-conservation-of-momentum-and-give-one-short-worked-ex-9174

Define conservation of momentum and give one short worked example.

# Conservation of Momentum **Definition:** The total momentum of a closed system remains constant when no external forces act on it. Mathematically: **p⃗₁ + p⃗₂ + ... = constant** or **Total momentum before = Total momentum after** --- ## Worked Example **Problem:** A 2 kg ball moving at 5 m/s collides head-on with a stationary 3 kg ball. After collision, they stick together. Find their final velocity. **Solution:** *Before collision:* - Ball 1: m₁ = 2 kg, v₁ = 5 m/s - Ball 2: m₂ = 3 kg, v₂ = 0 m/s *After collision:* - Combined mass: (m₁ + m₂) = 5 kg, velocity = v *Apply conservation of momentum:* m₁v₁ + m₂v₂ = (m₁ + m₂)v (2)(5) + (3)(0) = (5)v 10 = 5v **v = 2 m/s** The combined balls move at 2 m/s in the original direction.