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GuDViN [60]
3 years ago
10

What is the observed frequency of a siren with a frequency of

Physics
1 answer:
Yakvenalex [24]3 years ago
7 0

Answer: The observed frequency is 518.6 Hz

Explanation:

By the Doppler Effect, we know that:

f' = ((v + v0)/(v - vs))*f

where f' is the perceived frequency.

v is the velocity of the wave, in this case 330m/s

v0 is the velocity of the receptor, in this case 0m/s

vs is the velocity of the source, in this case -50m/s (the minus sign is because it is coming thowards us)

f is the original frequency, f = 440hz.

then we have:

f' = 440hz*(330m/s)/(330m/s - 50m/s) = 518.6 Hz

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Final exam answers for physical science apex?
Tju [1.3M]
First table:

1. For height, we usually use cm. If it is a must to use the conversion to solve for number 1, we can first convert the ft into m then to cm and then convert the in to cm and then add the values.

5ftx\frac{0.305m}{1ft}  = 1.525mx\frac{100cm}{1m} =152.5cm

then we convert the remaining 2in into cm and add it up:
2inx\frac{2.54cm}{1in}=5.08cm

152.5cm + 5.08cm = 157.58cm or 157.6cm

Another way to do this is to convert the ft to in and add it up to the remaining 2 in then convert to cm. The answer would be more or less the same. 

2. For weight, we will convert lbs to kg. 

105lbsx\frac{1kg}{2.2lbs} =  \frac{105kg}{2.2} = 47.7kg

3. For distance we will convert mi to km. 

1.1mix\frac{1.61km}{1mi} = 1.8km

4. The unit mph is miles per hour and we will want to convert that into kph or kilometers per hour. You will use the same method that you did above to get it. We do not need to convert hours anymore, so it will stay as is.

65 \frac{mi}{hr}x\frac{1.61km}{1mi} = 104.7\frac{km}{hr}

5. Now for the next one it is very straightforward because 1V = 1V no matter where you go. So if the given is 220V then that means that the converted value is also 220V. 

6. Now to convert Fahrenheit to Celsius, then all you have to do is use the formula given above and fill in what you know. 

The given is  70°F

°C = \frac{5}{9} (F - 32)
     = \frac{5}{9} (70 - 32)
     = \frac{5}{9} (38)
     = \frac{190}{9}
     = 21.1°C

The second table is very easy, all you need to do is convert the values to scientific notation or the other way around. All you need to do is move the decimal till you have a coefficient that is between 1 to 10 and then count how many times you moved the decimal. That will be the number or the exponent of 10. 

1. $150,000 = $1.5 x 10^5

If you moved the decimal to the left, the exponent will be positive. 

Now the other way around. To convert scientific notation to standard form, just move the decimal the number of places indicated by the exponent of 10. If it is positive, you will move to the right and if it is negative, you will move to the left. 

2. 2.59x10^6 = 2,590,000m

Now notice that the next value is less than 1. This means you will be moving the the decimal to the right to make it have a coefficient of 1 to 10. You need to move it 3 times to the right so that means the exponent will be negative. 

3. 0.005in = 5.0 x 10^(-3)in

Now do not forget to put in your units. In math or even in science the unit is EXTREMELY IMPORTANT. 

Hope this helped you and good luck!
4 0
3 years ago
Two force vectors are oriented such that the angle between their directions is 38 degrees and they have the same magnitude. If t
Usimov [2.4K]

Answer:

Sum of the forces will be equal to 3.479 N

Explanation:

We have given two same forces are oriented at an angle of 38°

Magnitude of each force is given F_1=F_2=1.84

We have to find the sum of the forces

Sum of the forces will be equal to

F=\sqrt{F_1^2+F_2^2+2F_1F_2cos\Theta }

So sum of the forces will be equal to F=\sqrt{1.84^2+1.84^2+2\times 1.84\times 1.84\times cos38^{\circ} }=3.479

So sum of the force will be equal to 3.479 N

6 0
3 years ago
Fluid pressure changes with depth are assumed to be linear. Which statement best explains why this does not hold true for atmosp
ankoles [38]

Answer:

Explanation:

Pressure due to fluid is directly proportional to the depth of fluid, density of the fluid and the value of acceleration due to gravity.

P = h d g

Where, h is the depth, d be the density and g be the acceleration due to gravity.

If we talk about teh atmospheric pressure, the density of air goes on decreasing as we go up and up. o we cannot say that it is directly depends only on the depth of air, it also depends on the changing density of air.

4 0
3 years ago
A string under a tension of 36 N is used to whirl a rock in a horizontal circle of radius 3.6 m at a speed of 16.12 m/s. The str
ExtremeBDS [4]

Answer:

6010.457N

Explanation:

Centripetal acceleration = a= V²/R

At a radius of 3.6m and velocity of 16.12m/s,

Acceleration is

a = 16.12²/ 3.6 = 72.182 m/s²

Force = Mass (m) * Acceleration (a)

36 = m * 72.182

m = 36/72.182

At breaking point

Radius = 0.468 m and Velocity = 75.1 m/s

a = V²/R = 75.1²/0.468

a = 12051.3 m/s

F = Mass(m) * Acceleration (a)

F = m * 12051.3

m = F/ 12051.3

Settings the ratio of mass equal

m = m

=> 36/72.182 = F/12051.3

F = 12051.3 * 36/72.182

F = 6010.457N

3 0
3 years ago
Why is it good practice for scientists to repeat trails
tensa zangetsu [6.8K]
It makes the data thet they collect more reliable so if they need the data again, they have already tested it a few times so therefor they know that it is right.
8 0
3 years ago
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