Final speed after inelastic collision: 6kg and 2kg masses

Practice question

Question

A 6kg mass at 4m/s collides inelastically with a stationary 2kg mass. What is the final speed?

Options

Choose one · Correct answer highlighted

3 m/s Correct 2.4 m/s 3.6 m/s 5 m/s

Explanation

Momentum conservation: 6×4=(6+2)vf⇒24=8vf⇒vf=3m/s. As per NCERT Chapter 3, equations v=u+at, s=ut+½at², v²=u²+2as describe uniformly accelerated motion. Applying correct signs and units gives 3 m/s as the result, so option A is correct.

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