- #1
bigbosswilly
- 4
- 0
- Homework Statement
- Penny (m=31kg) is learning to fly. She is attached to a 9.5m long bungee cord that has a spring constant of 72N/m. She jumps off the platform with an initial velocity of 3.5m/s [up]. Calculate the maximum distance below the platform that penny will reach (before bouncing back up).
- Relevant Equations
- Energy conservation, Forces equations, Energy equations
I started off by finding when Fg=Fx:
(72)(x)=(31)(9.8)
x=4.2193m
After this I'm stuck and have a few things I'm confused about:
When the penguin's jumping, is there elastic energy? (because the rope's getting compressed? Or maybe not). Also, I know you can use energy conservation, but there's too many variables and I can't solve it.
For example, I tried:
Et1= Et2
Eg + Ek = Ee (when the penguin's jumping and at the maximum distance below ledge with reference level set there as well, so no Eg)
(9.8)(31)(h) + (0.5)(31)(-3.5)^2 = (0.5)(72)(x^2)
I don't have the answer to this problem, sorry, but I was still hoping someone can help guide me through.
(72)(x)=(31)(9.8)
x=4.2193m
After this I'm stuck and have a few things I'm confused about:
When the penguin's jumping, is there elastic energy? (because the rope's getting compressed? Or maybe not). Also, I know you can use energy conservation, but there's too many variables and I can't solve it.
For example, I tried:
Et1= Et2
Eg + Ek = Ee (when the penguin's jumping and at the maximum distance below ledge with reference level set there as well, so no Eg)
(9.8)(31)(h) + (0.5)(31)(-3.5)^2 = (0.5)(72)(x^2)
I don't have the answer to this problem, sorry, but I was still hoping someone can help guide me through.