Answer:
Here the source is moving away from the observer so frequency will be smaller than the actual frequency and since the speed is increasing so the frequency is decreasing with time so correct answer is
D) lower than the original pitch and decreasing as he falls.
Explanation:
As we know by the Doppler's effect of sound we have
so we will have

so here when source moves away from the observer with a some speed then the frequency of the sound observed by the observer is smaller than the actual frequency
Here we know that the speed of the source is increasing with time as the source is falling under gravity
So we can say that the pitch of the sound will decrease with time
Coal and oil.... Fossil fuel is formed from decaying plants/animals who were buried and eventually converted to crude oil, gas by the exposure to heat and the pressure of the earths crust. This takes about 1 million years to happen.
Answer:
The internet is most useful to them because they use it to communicate.
Explanation:
If I were to send a message to my brother in Florida, through the internet, while I'm in Pennsylvania he would get it in minutes. On the other hand if I were going to meet him and then explain what I wanted to tell him in person it would take a much longer time.