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

The diagram above is the heating curve for a solid, QR is the?

The above figure shows the motion of a progressive wave along a string. The particle motion of the medium is in direction?

If a concave lens of focal length 12cm is used to produce a real image four times the size of the object, how far from the lens must the object be placed?

Find the effective resistance in the diagram above