question_answer

A particle of mass moving eastward with a speed v collides with another particle of the same mass moving northwards with the same speed u. The two particles coalesce on collision. The new particle of mass 2 m will move in the  northeasterly direction with a velocity

A)  \[\frac{\sqrt{\upsilon }}{\sqrt{2}}\]                        

B)         \[\frac{\upsilon }{2}\]

C)  \[\frac{\upsilon }{\sqrt{2}}\]                       

D)         None of these

Correct Answer: C

Solution :

            \[mv\sqrt{2}=(m+m)v\] \[\therefore \]      \[{{v}_{f}}=\frac{mv\sqrt{2}}{2m}=\frac{v}{\sqrt{2}}\]