531 Hz. As ambulance approaches and 470ish as it proceeds past stationary person.
Doppler effect.
Used online calculator. Use negative 20 m/s approach and positive 20 m/s leaving or having passed the person
Answer:
Ionic compounds are formed from strong electrostatic interactions between ions, which result in higher melting points and electrical conductivity compared to covalent compounds. Covalent compounds have bonds where electrons are shared between atoms.
Explanation:
-Geographic north and south poles are determined by the earth's spin.
-Magnetic north and south is determined by the direction a compass points.
Hope this helps,
kwrob