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?

Truck traveling west on the highway experiences an acceleration to the east. what could be the cause of this acceleration

In positive numbers less than 1, the zeros between the decimal point and a non-zero number are blank significant

Aplayground merry-go-round has a radius of 4.6 m and a moment of inertia of 200 kg-m2 and turns with negligible friction about a vertical axle through its center. a child applies a 26.0 n force tangentially to the edge of the merry-go-round for 15.0 seconds. if the merry-go-round is initially at rest, how much work did the child do on the merry-go-round?