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.
If you keep them exactly the same distance apart, <em>then wrapping the soccer ball in layers of duct tap</em> will increase he gravitational force between them, because the mass of the soccer ball will increase slightly.
Answer:
m = 4.29 kg
Explanation:
Given that,
Mass of the object, m = 2.8 kg
Stretching in the spring, x = 0.018 m
Frequency of vibration, f = 3 Hz
Let m is the mass of the object that is attached to the spring. When it is attached the gravitational force is balanced by the force on spring. It is given by :
k = 1524.44 N/m
Since, 
m = 4.29 kg
So, the mass that is attached to this spring is 4.29 kg. Hence, this is the required solution.
Lydia is an example of an optimist. Optimists always look at the positive side of a particular situation. They believe in a positive result. Optimist always see "the bright side" as opposed to the pessimist. The word optimism comes from latin word "optimum" which means "the best".
