A 7kg mass at 6m/s collides inelastically with a stationary 5kg mass. What is the final speed?
Momentum conservation: 7×6=(7+5)vf⇒42=12vf⇒vf=3.5m/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.
Ref: NCERT Class 11 Physics > Chapter 3: Motion in a Straight Line > Topic: Straight Line Motion - Practice Set0