Ineed some w/ this:

a police car siren emits a frequency of 2010 hz when stationary. when it is driving toward a stationary car, the other driver hears a frequency of 2120 hz. how fast is the police car driving?

using the doppler's effect equation, i got the answer ±16.3, but that apparently isn't the correct answer.

edited: ohhh ok, i got it, answer is 17.7 whoops

where is the photo and the answer choices?

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.

elctricity and magnet is conversion to it