Answer:
a) The car was moving at a speed of 
b) The negative sign of 
denotes that the observer is coming towards the police car which is the source of the sound.
c) 
Explanation:
Given:
- original frequency of the source,
- speed of the source,
- velocity of the obstacle car be,
- speed of sound,
- observed frequency,
<u>Using the equation from the Doppler's effect:</u>
a)
The car was moving at a speed of
b)
The negative sign of denotes that the observer is coming towards the police car which is the source of the sound.
c)
Now when, 
Then, 
Using the Doppler's eq.:
Answer:
is correct
Explanation:
in my think, first this due to ray emitted from the light those ray may be affect our skin or party of body.
Let the sphere is having charge Q and radius R
Now if the proton is released from rest
By energy conservation we can say
now take square root of both sides
so the proton will move by above speed and
here Q = charge on the sphere
R = radius of sphere
Answer: The balance of oxygen and carbondioxide is made due to respreration and photosinthesis. As we leave carbon dioxide and take in oxygen the ballance of carbon dioxide and oxygen is made. And during the photosinthesis of plants the balance of carbon dioxide and oxygen is made.
Answer:
solar, wind, hydro, natural resources
