Two objects are connected by a light string passing over a light, frictionless pulley as shown in the figure below. The object of mass m1 = 4.80 kg is released from rest at a height h = 4.40 m above the table.
(a) Using the isolated system model, determine the speed of the object of mass m2 = 3.00 kg just as the 4.80–kg object hits the table.
(b) Find the maximum height above the table to which the 3.00–kg object rises.
KE = 1/2*mv^2
PE = mgh
The Attempt at a Solution
So, basically the answer is to combine the total changes in kinetic and potential energy, where nonconservative work equals zero.
But why? Why should these be treated separately instead of using a combined mass?