Answer:
Therefore the the highest frequency is 620Hz and lowest frequency is 580Hz
Explanation:
Given data
Source Frequency fs=600Hz
Length r=1.0m
RPM=100 rpm
The speed of the generator is calculated as:

Substitute the given values

For approaching generator the frequency is calculated as:

On the other hand,for the receding generator,Doppler's effect is expressed as:

Therefore the the highest frequency is 620Hz and lowest frequency is 580Hz
Answer:
The pressure must have increased in the process
Explanation:
The State Equation for gasses reads: 
where P is the gas' pressure, V its volume, n the number of moles of gas, R the gas constant and T the temperature in degrees Kelvin.
If the temperature of the gas doesn't change in the described process, the right hand side of the equation stays the same. If that is the case, given that when the Volume of the gas diminishes from 75 liters to 50 liters, then the pressure must have increased to keep that product "P * V" constant:

So the pressure must have gone up to 450 kilopascals.
Answer:
a North and South Pole :)
Explanation:
Yes it does.
On the periodic table, tin is #50 and Mercury is # 80.