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:

Answer:270joules
Explanation:KE = 1/2mv^2
KE = 1/2(60kg)(3.0)^2 = 270 Joules
We know that the change in momentum is equals to the product of force and time that is impulse (
). Therefore, we need to determine the value of that the water is in air by using the second equation of motion,

Here, u is initial velocity which is zero.
.
Thus, impulse

From Newton`s second law,

Therefore, impulse

Given,
and 
Substituting these values, we get
Change in momentum = impulse
.
Sound travels better in water