Answer:
993.52 Hz
Explanation:
The frequency of sound emitted by the stationery train is 1057 Hz.
The car travels away from the train at 20.6 m/s.
The frequency the observer hears is given by the formula:
where v = velocity of sound = 343 m/s
vo = velocity of observer
f = frequency from source
This phenomenon is known as Doppler's effect.
Therefore:
The frequency heard by the observer is 993.52 Hz.
Answer:
A
Explanation:
A and B are isotopes of one another but the same element
C and D are isotopes of one another but the same element
However, A and B have a different proton count than C and D, indicating different elements because the proton count is equivalent to the atomic number.
1. Cenozoic ERA
2. Mesozoic ERA
3. Paleozoic ERA