A 2 kg object moving at 3 m/s collides inelastically with a stationary 4 kg object and they stick together. What is their common velocity after the collision?
Show the answer and explanation
Correct answer
B. 1 m/s
Principle or equation
In an inelastic collision, momentum is conserved: m1v1 + m2v2 = (m1+m2)v_final.
Why this answer is correct
Initial momentum = 2×3 + 4×0 = 6 kg·m/s. After collision, total mass = 6 kg, so v_final = 6/6 = 1 m/s.
Example
A 1 kg ball at 4 m/s hits a 3 kg stationary ball and they stick: final velocity = (1×4)/(1+3) = 1 m/s.
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