Answer:

Explanation:
given,
length of ladder = 10 ft
let x be the distance of the bottom and y be the distance of the top of ladder.
x² + y² = 100
differentiating with respect to time we get
..............(1)
when x = 8 and y = 6 and when \dfrac{dx}{dt} = 1.4ft/s
from equation (1)
now,


let the angle between the ladders be θ

y = xtan θ




Explanation:
<em>Given </em>
<em>wavelength </em><em>=</em><em> </em><em>4</em><em> </em><em>m</em>
<em>speed </em><em> </em><em>=</em><em> </em><em>3</em><em>3</em><em>2</em><em> </em><em>m/</em><em>s</em>
<em>frequency </em><em>=</em><em> </em><em>?</em>
<em>We </em><em>know </em><em>we </em><em>have </em><em>the </em><em>formula </em>
<em>wavelength</em><em> </em><em>=</em><em> </em><em>speed </em><em>/</em><em> </em><em>frequency </em>
<em>4</em><em> </em><em>=</em><em> </em><em>3</em><em>3</em><em>2</em><em> </em><em>/</em><em> </em><em>frequency </em>
<em>frequency </em><em>=</em><em> </em><em>3</em><em>3</em><em>2</em><em>/</em><em>4</em>
<em>Therefore </em><em> </em><em>frequency </em><em>is </em><em>8</em><em>3</em><em> </em><em>Hertz </em><em>.</em>
Answer:

Explanation:
When the unpolarized light passes through the first polarizer, only the component of the light parallel to the axis of the polarizer passes through.
Therefore, after the first polarizer, the intensity of light passing through it is halved, so the intensity after the first polarizer is:

Then, the light passes through the second polarizer. In this case, the intensity of the light passing through the 2nd polarizer is given by Malus' law:

where
is the angle between the axes of the two polarizer
Here we have

So the intensity after the 2nd polarizer is

And substituting the expression for I1, we find:
