#### dishab

##### Member

- Joined
- May 26, 2008

- Messages
- 39

- Gender
- Male

- HSC
- 2010

a) Find for what values of V a collision in the air will occur. Find, in terms of V, the time and the height when collision occurs, and prove that the collision speed is V m/s.

b) Find the value of V for which they collide halfway up the cliff, and the time taken.

The answer for part a) is, for V greater or equal to 30m/s, they collide after 180/V seconds, 180/V^2 (V^2-900) meters above the valley floor.

b) V=30 sqaure root 2, 3 square root 2 seconds.

Any idea how to do this?