Springs and Impulse (how can I relate them)

[miniradman]

G'day

I have an assignment to do where I analyse the bio-mechanics of long jump. I figured that I could possibly use a spring as an analogy of what goes on in the foot at take-off. The Achilles Tendon acts like a spring. However, I'm not sure if impulse explains why springs jump to high. Because my understanding is that the longer the time of impulse, the smaller the force, and the smaller the time, the greater the force. I figured that since compressing a spring a lot would give it more momentum in the upwards direction, due to the extra time it takes and potential energy released.

In essence, I want to know if I can use impulse to explain how springs work

 

[voko]

I think you would be better off explaining that with energy rather than impulse. When a spring is compressed, it has a certain amount of energy stored in it. When it returns to the normal state, that energy is given to the object it accelerates. Thus the total change in the energy of the accelerated object is equal to the energy released by the spring.

 

[miniradman]

Yes, I thought energy could have proven more useful. However, I what I would like to get out of it is momentum. Could I relate it to momentum, or energy then momentum?

 

[voko]

I can't think of any direct way of correlating momentum to a spring. It seems that you have to deal either with the energy stored in the spring, or with the equation of motion directly.