A bat produces a sound at 17,250Hz and wavelength 0.019m. What is
the speed of the sound?

"an open tank has the shape of a right circular cone. the tank is 6 feet across the top and 5 feet high. how much work is done in emptying the tank by pumping the water over the top edge? note: the density of water is 62.4 lbs per cubic foot."

Light traveling in a medium with a refractive index 1.19 is incident on a plate of another medium with index of refraction 1.79. at what angle of incidence is the reflected light fully polarized?

Aforklift raises a box above the floor and does 2,000 j of work. if the forklift motor consumes 3,000 j of electrical energy from the battery to raise the box, what is the efficiency of the lift?