Levi observed properties of four different waves and
recorded observations about each one in his chart.
which statement is best supported by the table?
wave
observations
travels fastest
through metal
travels fastest
through air
travels more slowly
through water than
air
travels more slowly
at cool temperatures
wave w and y are light waves, wave z is a sound
waves, and it is impossible to tell what kind of wave
wave x is.
wave w is a light wave, waves x and y are sound
waves, and it is impossible to tell what kind of wave
wave zis.
waves w and z are sound waves, and waves x and y
are light waves
wave w is a sound wave, waves x and y are light
waves, and it is impossible to tell what kind of wave
wave zis

Air is held within a frictionless piston-cylinder container, which is oriented vertically. the mass of the piston is 0.45 kg and the cross-sectional area is 0.0030 m2. initially (state 1) the pressure of the gas is sufficient to support the weight of the piston as well as the force exerted by the atmospheric pressure ( 101.32 kpa). the volume occupied by the air within the cylinder in state 1 is 1.00 liter. one end of a spring (with spring constant k = 1000 n/m) is attached to the top of the piston, while the other end of the spring is attached to a stage that can move vertically. initially the spring is undeflected and therefore exerts no force. then the stage is then moved quasistatically downward a distance of 10.0 cm, at which point the system reaches state 2. the piston-cylinder is not insulated; rather it remains in diathermal contact with the surroundings, which are at a constant temperature of 300 k. what is the change of pressure within the container?

Ammonia enters the expansion valve of a refrigeration system at a pressure of 10 bar and a temperature of 18oc and exits at 6.0 bar. the refrigerant undergoes a throttling process. determine the temperature, in oc, and the quality of the refrigerant at the exit of the expansion valve.

The magnitude of the poynting vector of a planar electromagnetic wave has an average value of 0.939 w/m^2 . the wave is incident upon a rectangular area, 1.5 m by 2.0 m, at right angles. how much total electromagnetic energy falls on the area during 1.0 minute?