At the same time the girl is pushing the box, a boy is trying to straighten out an extension cord. While doing this, he sends a pulse through the cord traveling at the exact same speed as the box (11 m/s). If the pulse has a length of 0.75 meters, calculate its frequency.

With the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 1.90

If an electric circuit is not grounded it is best to reach out and touch it to provide the ground a. true or b. false

A200 g lead frying pan gains 2000 joules of heat. what is the change in temperature