Jim pushes hard on a rock that weighs 500 pounds. he pushes with a force of 50 pounds, but the rock doesn't move. how much work did jim do?

Yvette hangs a 2.4kg bird feeder in the middle of a rope tied between two trees. the feeder creates a tension of 480 n in each side of the the rope.

Find the dimensions and area of the largest rectangle that can be inscribed in the upper half of the ellipse. (give your answers in terms of a and b. enter the dimensions as a comma-separated list.)

How do the kidneys affect homeostasis