A ball is thrown horizontally from the top of a lower of unkown height .Ball strikes a vertical wall whose plane is normal to the plane of month of ball Collison is elastic and ball falls on ground exactly at the midpoints between the lower and the wall ball strikes the grouind at an angle of the `30^(@)` with horizontal .Find the hieght of the tower (in meter)

Answer

6

Explanation

Ap is the motion of projectile in absence of wall which is half of a normal projecttile with range R= 2 OP and angle of projetion `theta = 30^(@)` and height H
BP =OP =`(1)/(2)`OB=BP
`impliesOP=(3)/(2)OB`
`implies OP=(3)/(2)OB`
`impliesR=12sqrtsqrt(3m)`
`impliesH=(u^(2)sin^(2)theta)/(2g)`
`implies H=(1)/(2)((Sin^(2)theta)/(Sin 2theta)R=6`