A 55kg cart is pushed by a force of 225 n. what is the carts acceleration?

Two polarizers A and B are aligned so that their transmission axes are vertical and horizontal, respectively. A third polarizer

Reptile [31]

Answer:

Explanation:

Let the angle between the first polariser and the second polariser axis is θ.

By using of law of Malus

(a)

Let the intensity of light coming out from the first polariser is I'

$I' = I_{0}Cos^{2}\theta$ .... (1)

Now the angle between the transmission axis of the second and the third polariser is 90 - θ. Let the intensity of light coming out from the third polariser is I''.

By the law of Malus

$I'' = I'Cos^{2}\left ( 90-\theta \right )$

So,

$I'' = I_{0}Cos^{2}\theta Cos^{2}\left ( 90-\theta \right )$

$I'' = I_{0}Cos^{2}\theta Sin^{2}\theta$

$I'' = \frac{I_{0}}{4}Sin^{2}2\theta$

(b)

Now differentiate with respect to θ.

$I'' = \frac{I_{0}}{4}\times 2 \times 2 \times Sin2\theta \times Cos 2\theta$

$I'' = \frac{I_{0}}{2}\times Sin 4\theta$

7 0

3 years ago

How are human cheek cells and human skin cells similar and different

KonstantinChe [14]

Answer:

human cheek cell has got a nucleus, rbc doesnot

human cheek cell is found in the cheeks n made there whereas rbc is made in the bonemarrow and found in blood

human cheek cell serves the function of supplying nutrition to cheek by simply exchange while rbc transports oxygen around the body..

cheek cell can reproduce rbc cannot asit is non nucleated.The epithelial cells in the lining of the mouth are referred to as basal mucosa and divide roughly every 24 hours. They can easily be obtained through a simple swab or a mouth rinse. The cheek cell is very simple, but it contains the entire genetic makeup of the person's body. For this reason, cheek cells are frequently used to establish paternity and other investigations involving DNA. More recently, researchers have discovered that the cheek cell can be used to measure a person's likelihood of having high blood pressure.

A human cheek cell is thin, flat and irregularly shaped and has a large nucleus that contains the DNA. Its plasma membrane helps the cell to maintain suitable temperature while giving it its shape. Since it is selectively permeable, it only allows certain molecules into and out of the cell. Its cytoplasm contains water that dissolves nutrients and enzymes. It is an animal cell so it is different from plant cell.and the difference will be same as that with animal cell

6 0

3 years ago

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Ken wants to jump and have some fun too! Barbie loans Ken her bungee cord. Is this a good idea? Explain with evidence and reason

aliina [53]

Answer:To ensure a safe and thrilling jump you will determine the relationship between the jump height and the

number of rubber bands used to make the bungee cord. You must allow your Barbie doll to come as

close to the floor as possible without sustaining any injuries or fatalities.

Explanation:

5 0

3 years ago

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Explain why radio and television stations use different frequencies to broadcast programs.

Sedaia [141]

I'm not sure exactly what you're asking.

It could be

==> Why do radio stations use different frequencies from TV stations ?

or it could be

==> Why don't all radio stations, or all TV stations, use the same frequency ?

Radio and TV can't coexist among each other in the same "band"

of frequencies, because they use different amounts of "space" on

the dial. One analog TV channel uses enough dial space for about

600 AM radio stations, or 30 FM radio stations ! That's one click on

the TV channel knob !

So if they were all jumbled up together on the same dial and you

wanted to tune your radio from one AM station to another, you

might have to crank through enough space for 600 radio stations ...

or even 1200 or 1800 of them ... to go to the AM signal you want.

And maybe even worse than that ! I'm sure you've never heard what

a TV signal SOUNDS like on a radio. It is horrendous, and it is loud !

It sounds like a thousand cats shrieking at each other, and it never stops.

That's another good reason to move the TV transmissions to frequencies

where radios will never hear them. If radios just randomly tuned in to a

TV picture signal every now and then, a lot of people would be shocked

out of their socks. They would stop listening to radio, and thousands of

advertisers would not like that.

For the second question ...

OK, so we don't mix radio and TV in the same band of frequencies.

But why does each station need its own frequency ? Why not just

put every radio station on one frequency, and every TV station on

a single frequency that's different from the radio frequency ?

The answer is: It's because people don't want to listen to two radio

stations at the same time, or watch two TV movies at the same time.

We like to make our choice, and then watch them or listen to them

one at a time. And FREQUENCY is the only way our radios and TVs

know how to pick out ONE and ignore all the others.

If there are two, or 5 or 10 stations all on the same frequency within

10 or 20 miles from you, then when you tune your radio to that frequency,

you HEAR two, or 5 or 10, songs, church services, newscasts, political

speeches, or commercials, all at the same time.

So if all radio stations were on the same frequency, or all TV stations

were all on the same frequency, then any time you turned on your

radio or TV, you'd see or hear all of them together. Radio and TV

would completely lose their entertainment value, everybody would

give up watching and listening, and once again ... thousands of

advertisers would not like that.

After all, advertising is the main reason why we have so much radio and TV at all. The advertiser buys, the broadcaster sells, and YOUR eyes and ears are the product.

5 0

2 years ago

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To determine a waves' frequency, you must know the

kykrilka [37]

B. number of oscillations in a given period of time.

7 0

3 years ago

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