A compass needle points to the north because
A. the needle is magnetic and the Earth is not.
B. the Earth has strong gravity and the needle has weak gravity.
C. the Earth is like a big magnet and the needle is not magnetic.
D. both the Earth and needle are magnetic.

The sun generates both mechanical and electromagnetic waves. which statement about those wave is true?

Gunpowder residue is most likely to show up where on a shooters hands

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.