How Do You Calculate Initial Velocity from Jump Height?

[btr94]

Homework Statement

Standing position: 100cm
Lowered hip position: 77cm
Peak height: 140cm

Question "Use the peak height of the jump and the standing hip position to calculate the initial velocity of the jumper just after he left the ground"

Homework Equations

Unknown

The Attempt at a Solution

Unknown - I only know equations that require time. I know no time measurement in this problem.

The problem is a jumping problem. The variable above, in order, are:
1. Standing tall - from the floor to the hip
2. Crouched down to jump - from the floor to the hip
3. In mid-air at the peak of the jump - from the floor to the hip.

These were measured using a 2-meter stick.

 

[aimslin22]

You need to use the force formulas:

PE spring = 1/2kx^2
KE = 1/2mv^2