Answer:
a) 
b)
Explanation:
Let´s use Doppler effect, in order to calculate the observed frequency by the byciclist. The Doppler effect equation for a general case is given by:

where:





Now let's consider the next cases:




The data provided by the problem is:

The problem don't give us aditional information about the medium, so let's assume the medium is the air, so the speed of sound in air is:

Now, in the first case the observer alone is in motion towards to the source, hence:

Finally, in the second case the observer alone is in motion away from the source, so:

Answer:
6.9066 × 10⁻⁵ m
Explanation:
For constructive interference, the expression is:
Where, m = 1, 2, .....
d is the distance between the slits.
The formula can be written as:
....1
The location of the bright fringe is determined by :
Where, L is the distance between the slit and the screen.
For small angle ,
So,
Formula becomes:
Using 1, we get:

Thus, the distance between the central maximum is 3.00 cm
First bright fringe , m = 1 occur at 3.00 / 2 = 1.50 cm
Since,
1 cm = 0.01 m
y = 0.0150 m
Given L = 2.00 m
λ = 518 nm
Since, 1 nm = 10⁻⁹ m
So,
λ = 518 × 10⁻⁹ m
Applying the formula as:

<u>⇒ d, distance between the slits = 6.9066 × 10⁻⁵ m</u>
To me the basic difference is their frequency and wavelength.
For frequency :
Infrared < visible light < ultraviolet
For wavelength :
Infrared > visible light > ultraviolet
Answer:
Light with a wavelength of 100 nm is completely absorbed by the atmosphere. True
Light with a wavelength of 400 nm has the color of red. False
Light with a wavelength of 280 nm is in the ultraviolet region. False
Explanation:
Light of wavelength 0-100nm can be absorbed by the earths atmosphere
Ultraviolet light ranges between 320-400nm hence the statement above is false.
The wavelength of red colour is around 620-700nm hence the statement above is false.