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2 years ago

A television remote control uses infrared light with a wavelength of 940 nm. What is the frequency of the light?

Physics

1 answer:

Ronch [10]2 years ago

5 0

Answer:

Frequency = 3.19 * 10^14 Hz or 1/s

Explanation:

Relationship b/w frequency and wavelength can be expressed as:

C = wavelength * frequency, where c is speed of light in vacuum which is 3.0*10^8 m/s.

Now simply input value (but before that convert wavelength into meters to match the units, you do this by multiply it by 10^-9 so it will be 940*10^-9)

3.0 * 10^8 = Frequency * 940 x 10^-9

Frequency = 3.19 * 10^14 Hz or 1/s

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Light is reflected from a crystal of table salt with an index of refraction of 1.544. An analyser is placed to intercept the ref

Vitek1552 [10]

Answer:

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Explanation:

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3 years ago

A 65 kg box is lifted by a person pulling a rope a distance of 15 meters straight up at a constant speed. How much Power is requ

Y_Kistochka [10]

Answer:

Power is 1061.67W

Explanation:

Power=force×distance/time

Power=65×9.8×15/9 assuming gravity=9.8m/s²

Power=3185/3=1061.67W

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2 years ago

a sphere of diameter 6•0cm is moulded into a thin uniform wire of diameter 0•2mm.calculate the length of the wire in metres

Scilla [17]

The length of the wire is 36 m.

<u>Explanation:</u>

Given, Diameter of sphere = 6 cm

We know that, radius can be found by taking the half in the diameter value. So,

$\text { sphere radius, } R=\frac{D}{2}=\frac{6}{2}=3 \mathrm{cm}=3 \times 10^{-2} \mathrm{m}$

Similarly,

$\text { wire radius, } r=\frac{0.2}{2}=0.1 \mathrm{mm}=1 \times 10^{-3} \mathrm{m}$

We know the below formulas,

$\text {volume of sphere}=\frac{4}{3} \times \pi \times R^{3}$

$\text {volume of wire}=\pi \times r^{2} \times l$

When equating both the equations, we can find length of wire as below, where $\pi=\frac{22}{7}$

$\frac{4}{3} \times \pi \times R^{3}=\pi \times r^{2} \times l$

$\frac{4}{3} \times \frac{22}{7} \times\left(3 \times 10^{-2}\right)^{3}=\frac{22}{7} \times\left(1 \times 10^{-3}\right)^{2} \times l$

The $\pi$ value gets cancelled as common on both sides, we get

$\frac{4}{3} \times 27 \times 10^{-6}=10^{-6} \times l$

The $10^{-6}$ value gets cancelled as common on both sides, we get

$l=4 \times 9=36 m$

7 0

3 years ago

Question 7

erastova [34]

gdj dhbdh sbctcrxrxvh7sdchhcsh

4 0

3 years ago

A young child is playing with a very flexible hose. She is moving her hand back and forth making transverse type waves. She move

aev [14]

Answer:

The waves will increase in frequency

Explanation:

As the young girl moves her hand back and forth faster, it will be observed that number of back and forth motions increase every second. Also the distance between crest and trough of the wave (wavelength) will be reduced as she moves her hand back and forth faster.

Frequency = number of turns (moves) per second

The waves will increase in frequency since there will be more number of back and forth motions in every second.

Also,

The distance between crest and trough will be reduced, which implies that there will be decrease in waves wavelength.

This can also be verified using wave equation;

V = Fλ

At constant velocity,

F ∝ ¹/λ

Thus, decrease in wavelength will cause increase in frequency of the waves.

The right answer is : The waves will increase in frequency

5 0

3 years ago