Ammar SH said:
I have a similar question;
What makes a bungee cord safer than using a normal rope when jumping.?
I understand that its elasticity and Hooke's law explains that compression and expansions are created to transform energy which helps you make a safer jump but
What has impulse and change in momentum got to do with the bungee cord being better than the rope?
The issue with a rope vs a bungee cord is acceleration. In this case we refer to it as deceleration since it is negative acceleration. A normal rope isn't elastic. When it goes taut it doesn't stretch at all, it simply tries to stop your falling as quick as it can. This is very bad for you!
A similar experience happens in a car accident. The car collides with something and very quickly comes to a stop. Without safety features this can apply huge amount of G force to your body. What happens if your head suddenly weights 100 times normal? Broken neck. If we buckle up and have an airbag, then instead of you slamming into the steering wheel at 100g, you are gradually stopped over a much longer period of time, experiencing maybe 10g instead. Much better! (Just making up those numbers, I don't know what the actual amount is)
A bungee cord does the same thing. Instead of the rope, which stops your fall in about half a second, the bungee cord stretches, absorbing the energy of the fall over 5-10 seconds, making the deceleration much gentler and enabling you to survive the fall.
Acceleration = change in velocity, and velocity is one of the factors that determines momentum. So change in velocity = change in momentum = acceleration.
Impulse is simply a measure of how much momentum has changed. Accelerating quickly causes a larger impulse than accelerating slowly in the same amount of time.