Which of the following is true about natural selection? a.) it occurs over many generations b.) it can always be observed within a single generation c.) it causes mutations to occur d.) it causes less useful traits to be passed to offspring

Atwo-stage air compressor operates at steady state, compression 10m^3/min of air from 100 kpa and 300k to 1200 kpa. an intercooler between the two stages cools the air to 300k at a constant pressure of 350 kpa. the compression processes are isentropic. a) calculate the power required to run the compressor, in kw b) compare the result to the power required for isentropic compression from the same inlet state to the same final pressure.

One form of energy can be another type of energy. a. created to form b. transformed into c. destroyed and then created to form

At what time will the interfering waves have an amplitudeof zero?