Question

From the top of a tower , 2 particles A and B are projected simultaneously with speeds of 3m/s and 4m/s , respectively, in horizontally opposite directions at time t=0 , At time = (2root3/10)sec , the angle between their velocities is ???

Answer 1

Let they meet after time time t.vertical distance travelled by horizontal projectile is y.y = ut+12at2y = 0 + 0.5×10t2vertical distance travelled by angular projectile is 20-y20-y = uxt - 12gt220-12gt2 = 102×12- 12gt2t = 2 sHorizontal distance travelled in 2seconds.x1 = ut  = 10×2 = 20 mx2 =uxt 
=40m