Which of the following best explains why lightning occurs? A: The warm updraft heats air molecules to extreme temp
B: Positive and Negative ions build up and need to discharge
C: High pressure storms condense air into a high energy state
D: Thunderstorms pull energy up from earth to sustain themselves

The four giant gas points that are made primarily of lightweight elements are

Aplane travels 1000 miles in 5 hours .what is the planes average speed?

Two loudspeakers, 5.5 m apart and facing each other, play identical sounds of the same frequency. you stand halfway between them, where there is a maximum of sound intensity. moving from this point toward one of the speakers, you encounter a minimum of sound intensity when you have moved 0.33 m . assume the speed of sound is 340 m/s.part a) what is the frequency of the sound? part b) if the frequency is then increased while you remain 0.21 m from the center, what is the first frequency for which that location will be a maximum of sound intensity? express your answer to two significant figures and include the appropriate units.