In the diagram below, a heavy box is being lifted. what is the function of the pulley in this situation?

a to reduce the amount of input force needed
b to change the direction of the input force
c to increase the distance over which the input force is applied

An open cart is moving along a straight frictionless horizontal track. when rain starts falling vertically into the cart, what happens to the speed of the cart?

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

The heliocentric and the geocentric models of the solar system included these central principles