If two waves are out of phrase with each other and are moving through the same medium what will they undergo

Flywheels are large, massive wheels used to store energy. They can be spun up slowly, then the wheel's energy can be released qu

Kruka [31]

Answer: a) 1766 sec. b) 55.5 MJ c) 13.9 MW d) -12,944 Nm

Explanation:

a) The torque and the angular acceleration, are related by the following expression, which resembles very much to the Newton's 2nd Law for point masses:

ζ = I . γ, where ζ=external torque, I = rotational inertia and γ = angular acceleration.

We also know that a flywheel is a solid disk, so the rotational inertia for this type of body is equal to MR² / 2.

By definition, angular acceleration is the rate of change of angular velocity with time, so we can write the following:

γ = ωf -ω₀ / t

Assuming that the flywhel starts from rest, we know that ω₀ = 0, and ωf = 12,000 rpm.

As all the units are given in SI units, it is advisable to convert the rpm to rad/sec, as follows:

12,000 rpm = 12,000 rev. (2π/rev) . (1min/60 sec) = 400 π rad/sec

Returning to the original equation, we have:

ζ = MR² / 2 . (ωf/ t)

Replacing by the values, and solving for t, we have:

t = 250 Kg. (0.75)² m² . 400 π / 2. 50 Nm = 1,766 sec.

b) Due to the flywheel is just rotating, all the stored energy is rotational kinetic energy, which can be written as follows:

K = 1/2 I ωf² = 1/2 (MR²/2) ωf² = 1/4. 250 Kg. (0.75)² m². (400π)²

K= 55.5 MJ

c) Power is defined as energy delivered in a given time.

The energy delivered, is just the half of the originally stored value, i.e. , 55.5 MJ /2, equal to 27.75 MJ.

Dividing this value by 2.0 sec, we have the average power delivered to the machine, that we found to be equal to 27.75 MJ / 2s = 13. 9 MW

d) Using the same relationship than in a), we can write the following:

ζ = I. γ

I remains the same (as the flywheel is the same), so the only unknown is the angular acceleration.

Angular acceleration, by definition, is as follows:

γ = ωf - ω₀ / t

We know the value of ω₀, as it is the top speed value that we have already got,i.e., 400 π rad/sec.

We don't know the value for ωf, but we know the value of the rotational kinetic energy after 2.0 secs, which is equal to the half of the one we obtained in step b).

So, we can write the following:

Kf = 1/2 I ωf² = 1/2 (1/2 I ω₀²) ⇒ 1/ 2 ωf² = 1/4 ω₀² ⇒ωf = ω₀/√2

Replacing in the expression for angular acceleration:

γ = (ω₀/√2 - ω₀) / t = -0.29. 400. π/ 2 rad/sec²= -184.1 rad/sec²

Finally, we can get the torque as follows:

ζ = (250 kg. (0.75)² m² /2) . 184.1 rad/sec² = -12,944 Nm

6 0

3 years ago

Which of the following is true about the speed of light?

Kazeer [188]

Answer:

B. In a vacuum, it is a constant value that does not depend on the observer.

6 0

2 years ago

30 points plus brainliest for best answer no funny answers Assignment: Waves Concept Map Exploration Your concept map will compa

mihalych1998 [28]

Answer:

Waves: "The phenomenon in which any number of particles or the energy packets that originates from a transmitter travels in a direction and it is somehow directed towards a receiver end is called as waves."

Electromagnetic wave: The type of waves which do not require any sort of medium for the transformation process of the energy, as it is directed towards from a transmitter towards a receiver.

For example: Radio, IR , Ultra sonic waves etc.

Mechanical waves: The type of waves which requires some medium to transfer the energy packets from one place to another, or from one point to the other using some medium. As the medium can be solids,liquids, or any gaseous forms.

For example: Sound waves, seismic waves etc.

Explanation:

The transfer of energy in Mechanical waves and Electromagnetic waves:

Both, the waves are much different due ones basic requirement of a medium while the other don't require one. As the density of any medium if increased it will increase the speed of the wave propagation. And this any medium being more denser will result in high speed form mechanical waves.

While, the electromagnetic waves can pass through matters or elements easily with out having any obstruction faced in its path because presence of medium is no requirement for the wave propagation.

I hope this helps!!

6 0

4 years ago

What is Archimedes principle?

trasher [3.6K]

Archimedes' principle states that a body immersed in a fluid is subjected to an upwards force equal to the weight of the displaced fluid. This is a first condition of equilibrium. We consider that the above force, called force of buoyancy, is located in the centre of the submerged hull that we call centre of buoyancy.

6 0

2 years ago

Convert the following to relative uncertainties <br>a) 2.70 ± 0.05cm<br>b) 12.02 ± 0.08cm

DENIUS [597]

data which is expressed in form of following way

$a = a_o + \Delta a$