In the given figure points A and C are on the horizontal ground & A and B are in same vertical plane. Simultaneously bullets are fired from A, B and C and they collide at D. The bullet at B is fired horizontally with speed of `72/5 km//hr` and the bullet at C is projected vertically upward at velocity of `54/5 km//hr`. Find velocity of the bullet projected from A in `m//s`.

Answer

5

Explanation

For collision `u=sqrt(u_(B)^(2)+u_(C)^(2))=sqrt((75/5xx5/18)^(2)+(54/5xx5/18)^(2))=sqrt(4^(2)+3^(2))=5 m//s`