Answer:
Energy is found as:
E = 1.987·10⁻¹⁹ J
Explanation:
Energy of a single photon of infrared light can be found by using the following formula:
where
E = in Joules
h = Planck's constant = 6.627×10 ⁻³⁴ J
f = frequency in hertz
It can also be written as:
where
c = 2.998×10⁸ ms⁻¹
λ = wavelength
Wavelength is given in the question which is:
λ = 1×10⁻⁶m
Substitute all the values in the Energy formula
Given Information:
Frequency of horn = f₀ = 440 Hz
Speed of sound = v = 330 m/s
Speed of bus = v₀ = 20 m/s
Answer:
Case 1. When the bus is crossing the student = 440 Hz
Case 2. When the bus is approaching the student = 414.9 Hz
Case 3. When the bus is moving away from the student = 468.4 Hz
Explanation:
There are 3 cases in this scenario:
Case 1. When the bus is crossing the student
Case 2. When the bus is approaching the student
Case 3. When the bus is moving away from the student
Let us explore each case:
Case 1. When the bus is crossing the student:
Student will hear the same frequency emitted by the horn that is 440 Hz.
f = 440 Hz
Case 2. When the bus is approaching the student
f = f₀ ( v / v+v₀ )
f = 440 ( 330/ 330+20 )
f = 440 ( 330/ 350 )
f = 440 ( 0.943 )
f = 414.9 Hz
Case 3. When the bus is moving away from the student
f = f₀ ( v / v+v₀ )
f = 440 ( 330/ 330-20 )
f = 440 ( 330/ 310 )
f = 440 ( 1.0645 )
f = 468.4 Hz
Here, Carefully look at the graph.
When it is on x=10, it is approximately 10, (slightly less than 10)
Closest value would be 90, so y/x = 90/10 = 9
So, the density of the graph would be 9 g/cm³
In short, Your Answer would be Option D
Hope this helps!
