I would also like to know if mA has initial potential energy, since it is slight
ID: 306523 • Letter: I
Question
I would also like to know if mA has initial potential energy, since it is slightly off the ground to start?
Two objects are connected by a massless rope that goes over a massless pulley as shown in the figure Use energy principles to determine how fast block B is traveling when it hits the ground, if mB > mA. mB mA d Make a drawing of the initial conditions, labeling the speeds and heights of each object. Then make a drawing of the final conditions, labeling the speeds and heights of each object. Then write out the energy equation for the system of objects. Finally solve this for the final speeds of the objects.Explanation / Answer
No, d has to be treated very larger than length of mA or its initial height. However in any case it wont have any effect on the answer, even if it is slightly above ground because the difference in PE of mA is mAgd as it travels d distance
Decrease in PE = increase in KE
-mAgd + mBgd = 0.5(mA+mB)v^2....equation for both particals, you can right separately and add them.
(mB-mA)gd = 0.5(mA+mB)v^2
v = sqrt(2*(mB-mA)gd/(mA+mB))