Concept:In projectile motion, the horizontal component of velocity remains constant because there is no horizontal acceleration.Explanation:The ball is hit with speed v making an angle of 60∘ with the vertical.Therefore, its angle with the horizontal is:90∘−60∘=30∘The initial horizontal component of velocity is:ux=vcos30∘Since cos30∘=23, we get:ux=23vAfter some time, the velocity makes an angle of 60∘ with the horizontal.Let the speed at this instant be V.Its horizontal component then is:Vcos60∘Because horizontal velocity is conserved:Vcos60∘=23vUsing cos60∘=21:V×21=23vSolving for V:V=3vThus, the speed of the ball at that instant is 3v.This matches option B.Answer:3v (Option B)