Blocks of 10 kg and 4 kg are connected by a spring on a frictionless surface. An impulse gives the 10 kg block velocity 14 m s⁻¹ toward the lighter block. Velocity of centre of mass is:
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Blocks of 10 kg and 4 kg are connected by a spring on a frictionless surface. An impulse gives the 10 kg block velocity 14 m s⁻¹ toward the lighter block. Velocity of centre of mass is:

G1 Physics · Accepted Answer

With zero external horizontal force, the centre of mass has constant velocity and ΣmᵢΔxᵢ = 0 in the centre-of-mass relation. Applying this to the given motion gives C: 10 m s⁻¹.