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1. The problem statement, all variables and given data
A mass hangs in balance on a elastic rope (k= 800 N/m). The length of the rope in balance is 1m. They pull the mass 25 cm out of balance. The mass colides with the ceiling (restitution coefficient = 0,8). How far extend the rope after the collision. ( Solution: 0,0113m)
In balance: m*g=k*u
Ek=1/2 m v2
Ep= m*g*h
Ev= 1/2 k u2
I have tried different things with using the law of conversation of energy. But I think a have not enough known date. So, I compared the energy of the moment when the mass is pulled 25cm out of balance with the moment it collides with the ceiling:
1/2 k (u+0,25)2=1/2 m v2+ m g 1,25
I want to determine the speed. Then I know that the speed after the collision is equal to 0,8v. Then I would use the law of conversation of energy again to determine the extending of the rope. TO determine v I think have not enough data but maybe I forgot something. Can anyone help me? Thanks a lot!
A mass hangs in balance on a elastic rope (k= 800 N/m). The length of the rope in balance is 1m. They pull the mass 25 cm out of balance. The mass colides with the ceiling (restitution coefficient = 0,8). How far extend the rope after the collision. ( Solution: 0,0113m)
Homework Equations
In balance: m*g=k*u
Ek=1/2 m v2
Ep= m*g*h
Ev= 1/2 k u2
The Attempt at a Solution
I have tried different things with using the law of conversation of energy. But I think a have not enough known date. So, I compared the energy of the moment when the mass is pulled 25cm out of balance with the moment it collides with the ceiling:
1/2 k (u+0,25)2=1/2 m v2+ m g 1,25
I want to determine the speed. Then I know that the speed after the collision is equal to 0,8v. Then I would use the law of conversation of energy again to determine the extending of the rope. TO determine v I think have not enough data but maybe I forgot something. Can anyone help me? Thanks a lot!