J & K CET Medical
J & K - CET Medical Solved Paper-2009
question_answer
A child stands at one end of a boat moving with a speed v in still water. If the child starts running towards the other end of the boat with a speed u, the centre of mass of the system (boat and child) will move with a speed
A) v - u
B) v
C) u
D) v +u
Correct Answer:
B
Solution :
External force on the system is zero, therefore velocity of centre of mass does not change. It remains v.