A body is thrown horizontally from the top of a tower and strikes the ground after three seconds at an angle of `45^@` with the horizontal. Find the height of the tower and the speed with which the body was projected. (Take ` g = 9.8 m//s^2`)

Explanation

Here, `u=? T=2 sec., bera =45 ^(@), , y= ?`
Tan beta =v_(y)/v_(tx) =y_(y)/u = tan 45 ^(@) =1`
:. `u=v_(y) =gt =9.8 xx 2 =19.6 m//s`
`y=1/2 gt^(2) =1/2 xx 9.8 (2) ^(2) =19 .6 m`.