Question

Question #21594

Answer 1

When there is no air resistance, at maximum height all initial kinetic energy is converted to its potential energy. Mathematically
`1/2mv^2=mgh_max`
`=>h_max=v^2/(2g)`
Inserting given values and taking `g=9.81ms^-2` we get
`h_max=28^2/(2xx9.81)`
`h_max=39.96m`, rounded to two decimal places.

Answer 2

`40m`

Explanation:

At max. height the vertical velocity is `0` (assume it is the final)

We can use the equation `(v_f)^2=(v_i)^2-2ad`

In this case `a` is the acceleration due to gravity (`9.8`)

Solve for `d` (the height)

`d=((v_f)^2-(v_i)^2)/(-2a)`

`color(white)d=(0-28^2)/((-2)(9.8))`

`color(white)d=40m`