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