Which example(s) below involve zero physics work? check all that apply. check all that apply. a rope supports a swinging chandelier. a person pushes a car stuck in the snow but the car does not move. a person uses a lawn mower on a lawn. a person pulls a sled uphill. a person holds a child?

When a vertical beam of light passes through a transparent medium, the rate at which its intensity i decreases is proportional to i(t), where t represents the thickness of the medium (in feet). in clear seawater, the intensity 3 feet below the surface is 25% of the initial intensity i0 of the incident beam. what is the intensity of the beam "10" feet below the surface? (give your answer in terms of i0. round any constants or coefficients to five decimal places.)

What kind of simple machine is a catapult?

Why does gravity have a lesser than grater effect on higher altitudes?