Physics questions

Question

A 5.2kg ball moving with a velocity of 11.6 m/s collides with a 3.3kg ball moving with a velocity of 4.3 m/s in the opposite direction. Find the common velocity of the balls (in m/s) if they coalesce on impact. (Enter the magnitude only)

Answer 1

Use conservation of linear momentum. Assuming the 5.2 kg ball moves in the positive direction, and the 3.3 kg ball moves in the negative direction,

m₁v₁ + m₂v₂ = (m₁ + m₂)v

v = (m₁v₁ + m₂v₂) / (m₁ + m₂)

m₁ = 5.2 kg

v₁ = 11.6 m/s

m₂ = 3.3 kg

v₂ = -4.3 m/s (note the negative sign)

Plug in the numbers, and get v in m/s. The magnitude is |v|.