Answer:
A police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase.
Explanation:
In Physics, Doppler effect can be defined as the change in frequency of a wave with respect to an observer in motion and moving relative to the source of the wave.
Simply stated, Doppler effect is the change in wave frequency as a result of the relative motion existing between a wave source and its observer.
The term "Doppler effect" was named after an Austrian mathematician and physicist known as Christian Johann Doppler while studying the starlight in relation to the movement of stars.
<em>The phenomenon of Doppler effects is generally applicable to both sound and light. </em>
An example of the Doppler effect is a police car with its siren on is driving towards you, and you perceive the pitch of the siren to increase. This is so because when a sound object moves towards you, its sound waves frequency increases, thereby causing a higher pitch. However, if the sound object is moving away from the observer, it's sound waves frequency decreases and thus resulting in a lower pitch.
<em>Other fields were the Doppler effects are applied are; astronomy, flow management, vibration measurement, radars, satellite communications etc. </em>
Answer:
W= F × d
W= 2kn × 3.6
W= 7.2 J
Work is measured in Joules!
To calculate the force between two negative charges, we use the formula which is given by the Coulomb`s Law as
Here, 
and
are the charges on the pith balls, r is the separation between the charges and k is constant and its value is 
.
Given 
and 
.
Substituting these values in above formula we get,
Thus, the repulsive force between two pith balls is 
.
Answer:
22.1 V
Explanation:
We are given that
Using 
We know that
In series
Substitute the values
Voltage across the 2.5 square cm wire=
Voltage across the 2.5 square cm wire=
Voltage across the 2.5 square cm wire=22.1 V
