A body at rest explodes into 3 parts in the ratio 1:1:2. Two equal parts move perpendicular to each other at 30 m/s and 40 m/s in a plane.

Question

A ball is dropped from a height 180 m. Two second later another ball is thrown down with speed u. The two balls cross each other at a height of 100 m, then the value of u will be:

(1) 20

(2) 30

(3) 40

(4) 60

Answer 1

Correct option is (2) 30