Rush please! 1500 points if answered I am not sure if I am answering these corre

Question

Rush please! 1500 points if answered

I am not sure if I am answering these correctly just want to check with the experts...

We were supposed to follow this link and then answer questions below:

http://www.physics.umd.edu/perg/abp/TPProbs/Problems/O/O38.htm

A. The sliders for the friction and spring stiffness have no numbers marked on them. Determine what they mean by changing them and seeing how the motion of a hanging mass changes. Does the "0" marker (the leftmost mark on the slider) correspond to the value "0" for friction? for spring stiffness (k)? Explain how you decided.

B. Set the slider for "stiffness of spring 3" in the middle (at the "5" mark). When it is set this way, do all three springs have the same spring constant? Explain how you decided. Can you find the spring constants of each of the springs? If you can, find them. If you can't, explain why you can't. When you change the slide for "stiffness of the spring 3" to a different value, do all the springs change together? Explain how you d ecided.

C. There are three masses on the right of the mass collection colored red, gold, and green. These are not labeled as to their mass. Can you find their masses? If you can, do it. If you can't, explain why you can't.

D. Turn on the display of the energy of 3. Determine where on the screen for what configurations of the mass and spring it defines the zero of the gravitational potential energy and for what configurations of the mass and spring it defines the zero of the elastic (spring) potential energy.

E. For this part of the problem, you are to watch the pattern of the energies change as the mass and spring oscillates. First, set a mass on one of the springs. Turn on maximum friction and let the mass come to rest. Move the dotted line to show where the equilibrium point is. Now turn off friction and move the mass to another spring at just the equilibrium point so it remains almost at rest. (This will restart the energy calculation.) Turn on the view of energy for your system. You should have some elastic PE and some gravitational PE.

Predict what you think will happen to the two potential energies and the total energy if you grab the mass and pull it down slowly. Then do it and see what happens. If it agrees with your prediction, explain the basis of your prediction. If it disagrees, explain what went wrong.

Now set the timing so that the mass is oscillating slowly and you can watch what happens to the energies. Pull the mass down and release it. Use the stopwatch to find an approximate time between the maximum values of each of the kinetic and the two potential energies. Is time between two maxima of the KE the same as between the two potential energies? If so, explain why. If not, explain why not.

Explanation / Answer

a) When spring stiffness is set to soft, the enlongation in spring is more when compared to the elongation when it is set to hard for the same mass. That means stiffness is more when it is hard and less when it is soft.

The "0" marker (the leftmost mark on the slider) correspond to the value "0" for friction for spring stiffness (k) as there is no loss in energy and motion will continue forever. It can be deduced from the fact that amplitude remains constant. If there had been some energy loss, amplitude would have been kept on decreasing.

b) When the slider for "stiffness of spring 3" in the middle (at the "5" mark), all the three spring have same elongation when we hang 100 gram .So, they have same stiffness.

We can find the spring constants of each of the springs by using equation F=kx. F will be equal to mass times acceleration due to gravity. x can be calculated using the scale given in the left.

When we change the slide for "stiffness of the spring 3" to a different value, stiffness of spring 3 changes only because the elongation of spring 3 changes only.

c) We can find the the value mass by using the stiffness of spring the we found in the previous step. We can use F=kx equation. x can be calculated using equation the scale given in the right. F/g will give the mass.

d) We have zero potential elastic and gravity for g=0 configuration.

e) Time between two maxima of potential and kinetic energy is same as total energy is conserved. When we have a maximum for potential energy, we have a minimum for kinetic energy and vice-versa.

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