Two balls A and B are projected from the same position with horizontal velocity 20 m s - 1 and 5 m s - 1 as shown. The separation between these two bodies at the moment their velocities become perpendicular to each other is x m . The value of x is

Step-by-step solution

v 1 → = 5 i ^ - g t j ^   ⇒ u 1 = 5 v 2 → = 20 i ^ - g t j ^   ⇒ u 2 = 20 As v 1 → and v 2 → are perpendicular, v → 1 · v → 2 = 0 t = u 1   u 2 g s → rel = u → rel × t =   ( u 1 + u 2 )   t = u 1 + u 2 u 1   u 2 g = 25 × 10 10 = 25   m