Machines A pulley system having 5 pulleys is used to
raise a 450 N load. Find the Mechanical
advantage and hence the effort if the
efficiency is 75%.

How does the image distance (di) of a convex lens compare with the image distance of a concave lens? a. the image distance of the convex lens is positive, and that of the concave lens is negative. b. both are negative for a virtual image. c. both are positive for a virtual image d. the image distance of the convex lens is negative, and that of the concave lens is positive.

The combining of light nuclei is called blank. blank as in not actually blank. you know what im tryin to say.

What causes the formation of ocean currents?