The figure above represents a frictionless pulley system in which a weight W is in equilibrium with a weight of 40N. Find the value of W

If a heavy barrel is rolled up a plane inclined at 30° to the horizontal. its velocity ratio will be?

A machine of velocity ratio 6 requires an effort of 400 N to raise a load of 800 N through I m. Find the efficiency of the machine

The efficiency of the pulley system shown above is 80%. find the effort E required to lift the load of 1200N

fig 4 represents a block-and-tackle pulley system on which an effort of W newtons supports a load of 120.0N if the efficiency of the system is 40% then the value of W is