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Bogdan [553]
3 years ago
14

a fan is rotating at 90 rpm.It is then switched off. It stops after 21 revolutions. calculate the time taken by the frictional t

orque is constant ​
Physics
1 answer:
fredd [130]3 years ago
6 0

Answer:

If the frictional torque is constant, the fan will slow down linearly from its original rotational speed of 90 rpm, equivalent to 1.5 rev/s. Linear slowdown implies that the average rotational speed until a complete stop is half of the top speed. Therefore the fan rotates at an average of 0.75 rotations per second. The time  t  to stop is therefore:

t=210.75  

=28  seconds

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The lowest note on a grand piano has a frequency of 27.5 Hz. The entire string is 2.00 m long and has a mass of 400 g. The vibra
Norma-Jean [14]

Answer:

1456 N

Explanation:

Given that

Frequency of the piano, f = 27.5 Hz

Entire length of the string, l = 2 m

Mass of the piano, m = 400 g

Length of the vibrating section of the string, L = 1.9 m

Tension needed, T = ?

The formula for the tension is represented as

T = 4mL²f²/ l, where

T = tension

m = mass

L = length of vibrating part

F = frequency

l = length of the whole part

If we substitute and apply the values we have Fri. The question, we would have

T = (4 * 0.4 * 1.9² * 27.5²) / 2

T = 4368.1 / 2

T = 1456 N

Thus, we could conclude that the tension needed to tune the string properly is 1456 N

4 0
3 years ago
Driving along a boring stretch of interstate in Illinois, you start experimenting using the average speed equation you learned i
astra-53 [7]
The average speed would be 33.29m/s.
The average speed equation is:

Average speed =  \frac{total distance}{total time}

First you will need to solve for the distance you traveled in each scenario. So we can solve this by getting the product of speed and the time traveled. 

Scenario 1:
Speed = 29m/s
Time = 120s
Distance = ?

Distance = (29m/s)(120s)
               = 3,480m

Scenario 2
Speed = 35m/s
Time = 300s
Distance = ? 

Distance = (35m/s)(300s)
               = 10,500m

Now that you have the distance of both, you can solve for your average speed. 

Average speed = \frac{total distance}{total time}
                                = \frac{3,480m+10,500m}{120s+300s}
                                = \frac{13,980m}{420s}
                                = 33.29m/s
5 0
3 years ago
Anything that has volume or mass
irinina [24]
Any object, except antimatter, :)

8 0
3 years ago
Volume is a measurement of the height of the wave known as what? <br><br><br> this is science
Cerrena [4.2K]
I’m gonna have to say “Ocean waves” as the answer
6 0
3 years ago
Read 2 more answers
Which letter represents the location of the<br> resister in this diagram?<br> A<br> B<br> C<br> D
ololo11 [35]

Answer:

The letter B is the letter that represents the location of the resister in the diagram.

Explanation:

I hope it helped!Please mark brainliest and have a wonderful night! and day!!!!

5 0
4 years ago
Read 2 more answers
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