How far does the jumper move horizontally?

Question

A long jumper achieves a height of 1.5 meters when her initial horizontal velocity is 5m/s. How far does the jumper move horizontally? (Hint: She reaches a height of 1.5 meters halfway through her jump.)

 

Please show work

Answer 1

from maximum height down using gravity

h=1.5 - 9.8 t^2

0=1.5 - 9.8 t^2

1.5= 9.8 t^2

0.153 = t^2

0.391 = t

this means that one half of the jump occurred over 0.391 seconds

so time of the total jump is 2t= 0.782

so then:

V x t = d

5 x 0.782 = 3.91 meters