Strings and Pulleys - Find the energy

[parwana]

Three objects with masses m1 = 7.0 kg, m2 = 10.0 kg, and m3 = 14.0 kg, respectively, are attached by strings over frictionless pulleys, as indicated in Figure P5.32. The horizontal surface is frictionless and the system is released from rest. Using energy concepts, find the speed of m3 after it moves down a distance of 2.0 m.

 

[arildno]

Interesting problem!
Does it interest you sufficiently to do some work on your own?

 

[parwana]

I don't understand how to set it up.

 

[arildno]

Let for example the floor be the level of zero potential energy.
What is then the mechanical energy of the system initially, and how does that quantity develop over the time?

Since the strings are taut and inextensible, how must the speeds be related to each other?

 

[semc]

hmm...consider COE