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ZanzabumX [31]
3 years ago
5

A. Telephone signals are often transmitted over long distances by microwaves. What is the frequency of microwave radiation with

a wavelength of 3.0 cm?
b. Microwave signals are beamed between two mountaintops 50 km apart. How long does it take a signal to travel from one mountaintop to the other?
Physics
1 answer:
zzz [600]3 years ago
6 0

(a) 10 GHz is the frequency of microwave radiation.

(b) 0.167 ms is required by the microwave to travel between two mountains.

Answer:

Explanation:

(a). 1 MHz is the frequency of microwave radiation.

(b)  0.167 ms is required by the microwave to travel between two mountains.

Answer:

Explanation:

a. Frequency is the measure of number of times a same thing will be repeated in a given time interval for a given time. And wavelength is the measure of distance between two successive crests or troughs. So wavelength and frequency are inversely proportional to each other. And velocity of light is the proportionality constant.

So frequency of microwave radiation = Speed of light/Wavelength of radiation

Frequency = \frac{3*10^{8} }{3*10^{-2} }

Frequency = 10^{8+2} = 10^{10}=10 GHz

So 10 GHz is the frequency of microwave radiation.

b). As microwave is a part of light waves, so it will be experiencing the speed of light.

As the speed is 3*10^{8} m/s and the distance between the two mountains is given as 50 km, then time can be calculated as

Time = Distance/Velocity

Time = \frac{50*10^{3} m}{3*10^{8} }=16.67*10^{3-8}=16.67*10^{-5}

So time = 0.167 ms.

Thus, 0.167 ms is required by the microwave to travel between two mountains.

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cestrela7 [59]

Answer:

160 years.

Explanation:

From the question given above, the following data were obtained:

Initial count rate (Cᵢ) = 400 count/min

Half-life (t½) = 40 years

Final count rate (Cբ) = 25 count/min

Time (t) =?

Next, we shall determine the number of half-lives that has elapse. This can be obtained as follow:

Initial count rate (Cᵢ) = 400 count/min

Final count rate (Cբ) = 25 count/min

Number of half-lives (n) =?

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25 = 1/2ⁿ × 400

Cross multiply

25 × 2ⁿ = 400

Divide both side by 25

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2ⁿ = 16

Express 16 in index form with 2 as the base

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Finally, we shall determine the time taken for the radioactive material to decay to the rate of 25 counts per minute. This can be obtained as follow:

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t = 4 × 40

t = 160 years.

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7 0
2 years ago
Which data set has the largest range? A. 55, 57, 59, 60, 61, 49, 48 B. 21, 25, 14, 16, 29, 22, 20 C. 12, 15, 16, 19, 18, 15, 27
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A vector is  a physical quantity which has  magnitude as well direction  for its complete specification.

The magnitude of a physical quantity is simply a  numerical number .Hence it can not be negative.

A negative vector is a vector which comes into existence when it is opposite to our assumed direction with respect to any other vector.  For instance, the vector is taken positive if it is along + X axis and negative if it is along - X axis.

As per the first option it is given that a vector is negative if its magnitude is greater than 1. It is not correct as magnitude play no role in it.

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Third one tells that a vector is negative if its displacement is along north. It does not give any detail information about the negativity of a vector.

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7 0
3 years ago
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The apparent height of a building 10.5 km away is 0.02 radians. What is the approximate height of the building to the nearest me
Ksenya-84 [330]

Answer:

Approximate height of the building is 23213 meters.

Explanation:

Let the height of the building be represented by h.

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0.02 radians  = 1.146°

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Applying the trigonometric function, we have;

Tan θ = \frac{opposite}{adjacent}

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h = 23213 m

The approximate height of the building is 23213 m.

8 0
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