The trigonometric ratios are sine, cosine and tangent. We can use cosine to find the length of the shadow from the calculation as 1.7 ft.
<h3>What is trigonometric ratio?</h3>
The term trigonometric ratio has to do with sine, cosine and tangent which are used to solve problems that involve the right angled triangle.
Using the geometry of the right angle triangle, we can find the tangent of the angle 30 in order to obtain the length of the shadow.
Tan 30° = opp/3
opp = 3Tan 30°
opp = 1.7 ft
The length of the girl's shadow from the calculation is 1.7 ft.
Learn more about tangent: brainly.com/question/14022348
100.000 kilometres, it takes half an hour.
Answer:
Explanation:
Let the thickness of the film is t and the refractive index of the material of film is n.
When light travels through a sheet of thickness t, the optical path traveled is nt.
When the path of one of slit is covered by a sheet of thickness t, the optical path becomes
x = ( n - 1) t
As the one fringe is shift, so the optical path changed by one wavelength.
i.e., x = λ
So, λ = ( n - 1) t

Answer:
4.62 s
Explanation:
We are given that
Initial angular speed,



Substitute the values






Hence, the wheel takes 4.62 s to come to rest.