The 30revs is at the motor axis, there could be a reduction in between for example. And yes this 30revs corresponds with 1,4 m/s of the cage. But i don't see how this will get me Ekin.
Ah so 1 torque is calculated for the work done by lifting the cage 15m in the air and the 2nd is because of the moment of inertia of the system. But the pulley radius or inertia of pulley or motor is not given. So how am i supposed to calculate the kinetic energy?
Homework Statement
A loaded elevator acge has a mass of 1500kg and a countermass of 1000kg. The cage is accelerated with 2m/s² to 1,4m/s and lifted to a height of 15m and stops at stand still. The inertia of the motor or the radius of the cablewheel is NOT given. The steady state speed of the...