Impulse of vertical jump

[gopi9]

Hi

If a person jumps(countermovement jump) then there would be 2 impulses that is the 1st impulse would be when person sits down, getting ready to jump and the 2nd impulse would be when he jumps back on to the ground.
1)I want to know the relationship between these 2 impulses.
2) How can we compare these 2 impulses??
3)Can we plot graph for these 2 impulses versus time?

 

[gopi9]

I am not from physics background. I am very good at these stuff.
So please help me

 

[haruspex]

Your question is not very clear. What is a "countermovement" jump?
In your two impulses, you left out the most obvious - the take-off. Let's just compare take-off and landing.
Ignoring air resistance, and assuming the same posture for the instant of take-off and the instant of landing, the take-off and landing speeds will be the same. It follows that the momenta (impulse) will be the same, just in opposite directions.