Two projectiles are thrown from point A & B, towards each other, A and B are separated by 130 m. A is thrown with 20 m/s. Calculate the minimum velocity in m/s with which B is to be thrown, such that they just meet on the ground? (the projectiles can be thrown at any angle) [take g = 10 m/s2]
For both the projectiles, the angle of projection must be equal to 45∘ so as to reach maximum range.
x+y = 130
For projectile A,
x=u2Agsin90∘=20×2010=40
So, y=130-40 = 90
Now, for the projectile B,
90=u2Bsin90g
u2B=900⇒uB=±30
Hence, x=30ms which is the velocity of B required for two projectiles to meet.