The frequency of bird chirping hear by hiran will be 1.77 kHz.
<u>Explanation:</u>
As per Doppler effect, the observer will feel a decrease in the frequency of the receiving signal if the source is moving away from the observer. So the shifted frequency is obtained using the below equation:

Here , c is the speed of sound, Vs is the velocity of source with which it is moving away. f is the original frequency of source and f' is the frequency shift heard by the observer.
As here, f = 1800 Hz, Vs= 6 m/s and c = 343 m/s, then

So, the frequency of bird chirping hear by hiran will be 1.77 kHz.
Answer:30 cm
Explanation:
Given
object distance 
focal length of concave mirror 
height of object 
Using mirror formula




and magnification is



So height of object is same as of object .
Position :image is formed at the spot where object is placed.
The average it the constant speed.
Answer:
the answer is 45.6 kg = 45600 g
Answer:
Yes, Centripetal Force acts on the Car.
Explanation:
When a car undergoes a circular motion, a centripetal force acts onto it.
Centripetal Force = [m*(v^2)]/R , where
- R is the radius of curve
- v is the constant speed
- m is the mass of the car