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Mandarinka [93]

2 years ago

11

A plane flies at 200 m/s, emitting a 600 Hz roar. Assuming a 340 m/s speed of sound, what will be the frequency of sound waves h

eard by a stationary observer directly behind the plane? I NEED THIS ASAP PLEASE
A. 247 Hz

B. 260 Hz

C. 378 Hz

D. 400 Hz

1 answer:

stepladder [879]2 years ago

7 0

Answer:

378 Hz

Explanation:

When source of sound moves away from stationary listener

f' = f x V / ( V + Vs)

f' = 600 x 340 / ( 340 + 200)

f' = 204000/540

f' = 378 Hz

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Thomas and John are carrying a 43kg cylinder head on a 510cm X 510mm board. The cylinder head with dimensions of 43cm X 250mm li

tatyana61 [14]

John carry the heaviest load.

<h3>How to find out who is carrying the heavy load?</h3>

Write down given data from questions:

Board=510cm X 510mm.

Cylinder head with dimensions=43cm X 250mm.

Cylinder lies across the board 210cm from john.

Find out: Who is carry the heaviest load?

Calculation:

We assume that mass of cylinder head = x kg

Then weight=x x 9*81

W=9.81x Newton.

Weight per unit length= Weight/Total leanth

Weight per unit length= 9.81x/43

(w/l)=0.23x N/cm

From equation contition: $(F_{J} +F_{T} =9.81x n)$

$F_{T} (510)=9.81x$ (210+21.5)

$F_{T} (510)=9.81 x (231.5)$

$F_{T} =4.452x N.$

$F_{J} =9.81x-4.452x$

$F_{J} =5.358 xN$

Therefore $F_{J} \geq F_{T}$

To learn more about mass per unit length, refer to:

brainly.com/question/24180692

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4 0

1 year ago

10. How far does a transverse pulse travel in 1.23 ms on a string with a density of 5.47 × 10−3 kg/m under tension of 47.8 ?????

KATRIN_1 [288]

Answer: Tension = 47.8N, Δx = 11.5× $10^{-6}$ m.

Tension = 95.6N, Δx = 15.4× $10^{-5}$ m

Explanation: A speed of wave on a string under a tension force can be calculated as:

$|v| = \sqrt{\frac{F_{T}}{\mu} }$

$F_{T}$ is tension force (N)

μ is linear density (kg/m)

Determining velocity:

$|v| = \sqrt{\frac{47.8}{5.47.10^{-3}} }$

$|v| = \sqrt{0.00874 }$

$|v| =$ 0.0935 m/s

The displacement a pulse traveled in 1.23ms:

$\Delta x = |v|.t$

$\Delta x = 9.35.10^{-2}*1.23.10^{-3}$

Δx = 11.5× $10^{-6}$

With tension of 47.8N, a pulse will travel Δx = 11.5× $10^{-6}$ m.

Doubling Tension:

$|v| = \sqrt{\frac{2*47.8}{5.47.10^{-3}} }$

$|v| = \sqrt{2.0.00874 }$

$|v| = \sqrt{0.01568}$

|v| = 0.1252 m/s

Displacement for same time:

$\Delta x = |v|.t$

$\Delta x = 12.52.10^{-2}*1.23.10^{-3}$

$\Delta x =$ 15.4× $10^{-5}$

With doubled tension, it travels $\Delta x =$ 15.4× $10^{-5}$ m

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3 years ago

There are free body diagrams in the picture, number (#). Which of the diagram(s) shows an object with a net force right?

ryzh [129]

4 only diagram net Force

6 0

3 years ago

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a man can row about 4kmperhr in a still water.he rows the boat 2km up the stream and 2km back to his starting point in 2hr.how f

Nat2105 [25]

<u>Answer</u>:

The stream flowing at a speed of $2.828 \mathrm{km} / \mathrm{hr}$

<u>Explanation</u>:

Given:

Distance = 2km (both in upstream and downstream)

The speed in still water be x km/hr.

The speed in upstream = 4-x

Speed in downstream = 4+x

Solution:

We know that, Speed = distance/time

So, Time = distance/speed

Therefore,

$2=\left(\frac{2}{4-x}\right)+\left(\frac{2}{4+x}\right)$

$2=\frac{2(4+x)+2(4-x)}{(4-x)(4+x)}$

$2(4-x)(4+x)=2(4+x)+2(4-x)$

$2(4-x)(4+x)=2(4+x+4-x)$

By cancelling 2 on both sides,

$16-x^{2}=8$

$x^{2}=16-8=8$

$x=\sqrt{8}$

$x=2.828 \mathrm{km} / \mathrm{hr}$

Result:

Thus the speed of the stream is $2.828 \mathrm{km} / \mathrm{hr}$

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3 years ago

Which device is using a motor?

Alexxx [7]

Out of all the options, only body massager which uses electric energy to move back and forth is using motor here. It is because a motor converts electrical energy to Mechanical energy and only massager obeys it among all the options.

In short, Your Answer would be Option C

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5 0

2 years ago

Read 2 more answers