What must be the thickness of, and the speed of sound in, a plastic layer having a density of 1500 kg/m3 if it is to transmit plane waves at 20 kHz from water into steel with no reflection? (b) What would be the intensity reflection coefficient back into water for normally incident wavesimpinging on an infinitely thick layer of this plastic?

Identify the correct relation showing that the radius r of the orbit of a moon of a given planet can be determined from the radius r of the planet, the acceleration of gravity at the surface of the planet, and the time τ required by the moon to complete one full revolution about the planet. determine the acceleration of gravity at the surface of the planet jupiter knowing that r = 71 492 km and that t= 3.551 days and r= 670.9 × 10^3 km for its moon europa.

Abowling ball rolling down the lane toward the pins has gravitational potential energy. a. no b. a lot of c. a little

If anyonee has done the momentum lab practical in physics can you give me the answers i am s lostt rnn : (