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2 years ago

At what angle should the axes of two Polaroids be placed so as to reduce the intensity of the incident unpolarized light to

Physics

1 answer:

mote1985 [20]2 years ago

6 0

Answer:

Ok, the question is incomplete buy ill try to answer this in a general way.

Suppose that you have no-polarized light.

When that light hits one polaroid, the light becomes polarized along some line, and has an intensity I0.

Now, when polarized light hits a polaroid which axis is at an angle θ with respect to the polarization of the light, the intensity of the resulting beam is given by the Malus's law:

I(θ) = I0*cos^2(θ)

For example, if the axis of the polaroid is exactly the same as the one of the polarized light, then we have θ = 0°

and:

I(0°) = I0*cos^2(0°) = I0

So the intensity does not change.

Now, knowing the initial intensity, you can find the angle needed to get a given intensity.

For example, if the question was:

"At what angle should the axes of two Polaroids be placed so as to reduce the intensity of the incident unpolarized light to A"

We should solve:

I(θ) = A = I0*cos^2(θ)

(A/i0) = cos^2(θ)

√(A/I0) = cos(θ)

Acos(√(A/I0)) = θ

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A box of mass M is pushed a distance Δ x across a level floor by a constant applied force F . The coefficient of kinetic frictio

Nat2105 [25]

Answer:

Final speed of the box after moving the given distance is

$v = \sqrt{\frac{2(F - \mu Mg)\Delta x}{M}}$

Explanation:

By work energy theorem we know that work done by all the forces is equal to the change in kinetic energy of the system

Here we know that work is done on the system by external force and friction force

So we will have

$F\Delta x - \mu M g \Delta x = \frac{1}{2}Mv^2 - 0$

$(F - \mu Mg)\Delta x = \frac{1}{2}M v^2$

so we have

$v = \sqrt{\frac{2(F - \mu Mg)\Delta x}{M}}$

8 0

2 years ago

A 2600-m-high mountain is located on the equator. how much faster does a climber on top of the mountain move than a surfer at a

puteri [66]

The climber move 0.19 m/s faster than surfer on the nearby beach.

Since both the person are on the earth, and moves with the constant angular velocity of earth, however there linear velocity is different.

Number of seconds in a day, t=24*60*60=86400 sec

The linear speed on the beach is calculated as

V1= $\frac{2πr}{t}$

Here, t is the time

Plugging the values in the above equation

V1= $\frac{2π*6.4*10^6}{86400}$ =465.421 m/s

Velocity on the mountain is calculated as

V2= $\frac{2π(r+h)}{t}$

Plugging the values in the above equation

V2= $\frac{2π(6.4*10^6+2600}{86400}$ =465.61 m/s

Therefore person on the mountain moves faster than the person on the beach by 465.61-465.421=0.19 m/s

5 0

2 years ago

Lydia is often described as having a positive outlook on life. She assumes the best of people and situations. Lydia exemplifies

HACTEHA [7]

Lydia is an example of an optimist. Optimists always look at the positive side of a particular situation. They believe in a positive result. Optimist always see "the bright side" as opposed to the pessimist. The word optimism comes from latin word "optimum" which means "the best".

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2 years ago

Read 2 more answers

Noise-canceling headphones are an application of destructive interference. Each side of the headphones uses a microphone to pick

jeka57 [31]

Answer:

2.5 ms

Explanation:

v = Speed of sound in air = 343 m/s

f = Frequency = 200 Hz

Wavelength is given by

$\lambda=\dfrac{v}{f}\\\Rightarrow \lambda=\dfrac{343}{200}\\\Rightarrow \lambda=1.715\ m$

In the case of destructive interference, path difference is given by

$x=\dfrac{\lambda}{2}\\\Rightarrow x=\dfrac{1.715}{2}\\\Rightarrow x=0.8575\ m$

Delay is givenn by

$t=\dfrac{x}{v}\\\Rightarrow t=\dfrac{0.8575}{343}\\\Rightarrow t=0.0025\ s$

The minimum headphone delay, that will cancel this noise is 2.5 ms

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2 years ago

Light from a lamp is shining on a surface. how can you increase the intensity of the light on the surface?

vlada-n [284]

The intensity of a light in a surface follows the inverse square law formula which can be mathematically expressed as,
I = k/d²
where I is intensity, d is distance, and k is the proportionality constant. For us to increase the intensity, we should lower the distance from the source to the surface.

4 0

2 years ago