Which of the following statements describes how a heat pump works?

1. the heat pump decompresses gas to warm and cool air.
2. the heat pump compresses gas to warm air and decompresses gas to cool air.
3. the heat pump compresses gas to warm and cool air.
4. the heat pump decompresses gas to warm air and compresses gas to cool air.

Which situation will have the highest resistance? a.long wire and high temperatureb.short wire and high temperaturec.long wire and cold temperaturedshort wire and low temperature

Alinearly polarized electromagnetic wave has an average intensity of 196 w/m^2. this wave is directed towards two ideal polarizers (in real polarizers, transmission is also effected by reflection and absorption). polarizer a is oriented with its transmission axis at an angle of θ_1=20.8∘ with the incident electric field. polarizer b has its axis at an angle of θ_2=63.0∘ with the incident electric field. what is the average intensity of the wave after it passes through polarizer a? what is the average intensity of the wave after it passes through polarizer b? suppose that the two polarizers a and b are interchanged. what would the average intensity be after passing through both polarizers?

Which is the correct symbol for an isotope of iodine with 53 protons and 78 neutrons?