Question

A projectile is thrown horizontally from top of a building of height 10 m with certain speed (u). At the same time another projectile is thrown from ground 10 m away from the building with equal speed (u) on the same vertical plane. If they collide after 2s, then choose the correct options. 
(a) the angle of projection for second projectile is 60º and u = 10ms-1 
(b) the angle of projection for second projectile is 90º and  = 5ms-1 
(c) the angle of projection for second projectile is 60º and u = 5ms-1 
(d) the angle of projection for second projectile is 45º and u = 10ms-1 
please send detailed solution.​

Answer 1

Answer:

correct option b

Explanation:

u½= 2ucos teta/2

Therefore tan teta /2 = 10/10= 1

teta =90°

2ucosteta /2×2 = 10√2

Ans u=5 ms-1