1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Alisiya [41]
3 years ago
11

It has been argued that power plants should make use of off-peak hours to generate mechanical energy and store it until it is ne

eded during peak load times. One suggestion has been to store the energy in large flywheels spinning on nearly frictionless ball bearings. Consider a flywheel made of iron (density 7800 kg/m3 ) in the shape of a 10.0 cm thick uniform disk.
(a) What would the diameter of such a disk need to be if it is to store 10.0 megajoules of kinetic energy when spinning at 90.0 rpm about an axis perpendicular to the disk at its center?

(b) What would be the centripetal acceleration of a point on its rim when spinning at this rate?
Physics
1 answer:
sdas [7]3 years ago
3 0

Answer:

Explanation:

90 rpm = 90 / 60 rps

= 1.5 rps

= 1.5 x 2π rad /s

angular velocity of flywheel

ω = 3π rad /s

Let I be the moment of inertia of flywheel

kinetic energy = (1/2) I ω²

(1/2) I ω² = 10⁷ J

I = 2 x  10⁷ / ω²

=2 x  10⁷ / (3π)²

= 2.2538 x 10⁵ kg m²

Let radius of wheel be R

I = 1/2 M R² , M is mass of flywheel

= 1/2 πR² x t x d x R² , t is thickness , d is density of wheel .

1/2 πR⁴ x t x d = 2.2538 x 10⁵

R⁴ = 2 x 2.2538 x 10⁵ / πt d

= 4.5076 x 10⁵ / 3.14 x .1 x 7800

= 184

R= 3.683 m .

diameter = 7.366 m .

b ) centripetal accn required

= ω² R

= 9π² x 3.683

= 326.816 m /s²

You might be interested in
a spring has a force constant of 100 n/m and an unstretched length of 0.07 m. one end is attached to a post that is free to rota
Digiron [165]

F equals 3N with respect to the circle's center, moving in the same direction as the centripetal acceleration.

<h3>How much centripetal force is there in a centrifuge?</h3>

Centripetal force is the force that pushes an item in the direction of its center of curvature. It is fundamental to how a centrifuge operates.

<h3>On a roller coaster, what is centripetal force?</h3>

An item travelling in a circle is pushed inward toward what is known as the center of rotation, which is essentially what a roller coaster accomplishes when it travels through a loop. The force that maintains an object moving along a curved route is this pull toward the center, or centripetal force.

To know more about centripetal force visit:-

brainly.com/question/11324711

#SPJ4

6 0
1 year ago
How is the medium of a wave and transmit of a wave similar and different?
zepelin [54]

Answer:

Sound and light are similar in that both are forms of energy that travel in waves. They both have properties of wavelength, freqency and amplitude. Here are some differences: Sound can only travel through a medium (substance) while light can travel through empty space.

3 0
3 years ago
12. A runner at the start of a race generates 250 W of power as he accelerates to 5 m/s. If the runner has a mass of
Margaret [11]
1/2 m/s2
30 Na




I hope this helps!
4 0
3 years ago
When it is summer at the South Pole,
Elza [17]
D

The northern hemisphere is experiencing winter because it is tilted away from the sun whereas the south experiences summer because it is tilted towards the sun
6 0
3 years ago
A 1300 kg steel beam is supported by two ropes. (Figure
Dmitriy789 [7]

Relative to the positive horizontal axis, rope 1 makes an angle of 90 + 20 = 110 degrees, while rope 2 makes an angle of 90 - 30 = 60 degrees.

By Newton's second law,

  • the net horizontal force acting on the beam is

R_1 \cos(110^\circ) + R_2 \cos(60^\circ) = 0

where R_1,R_2 are the magnitudes of the tensions in ropes 1 and 2, respectively;

  • the net vertical force acting on the beam is

R_1 \sin(110^\circ) + R_2 \sin(60^\circ) - mg = 0

where m=1300\,\rm kg and g=9.8\frac{\rm m}{\mathrm s^2}.

Eliminating R_2, we have

\sin(60^\circ) \bigg(R_1 \cos(110^\circ) + R_2 \cos(60^\circ)\bigg) - \cos(60^\circ) \bigg(R_1 \sin(110^\circ) + R_2 \sin(60^\circ)\bigg) = 0\sin(60^\circ) - mg\cos(60^\circ)

R_1 \bigg(\sin(60^\circ) \cos(110^\circ) - \cos(60^\circ) \sin(110^\circ)\bigg) = -\dfrac{mg}2

R_1 \sin(60^\circ - 110^\circ) = -\dfrac{mg}2

-R_1 \sin(50^\circ) = -\dfrac{mg}2

R_1 = \dfrac{mg}{2\sin(50^\circ)} \approx \boxed{8300\,\rm N}

Solve for R_2.

\dfrac{mg\cos(110^\circ)}{2\sin(50^\circ)} + R_2 \cos(60^\circ) = 0

\dfrac{R_2}2 = -mg\cot(110^\circ)

R_2 = -2mg\cot(110^\circ) \approx \boxed{9300\,\rm N}

8 0
2 years ago
Other questions:
  • Summarize how psychology is considered a science.
    8·2 answers
  • Sometimes it is very hard to hear in a gymnasium because of echoes . How can you changed it
    10·1 answer
  • When should you use a piece of pipe as a leverage extension on the handle on a wrench?
    5·1 answer
  • True or false? A proton carries a positive charge.
    7·1 answer
  • Light of a given wavelength is used to illuminate the surfacce of a metal, however, no photoelectrons are emitted. In order to c
    8·1 answer
  • During normal beating, a heart creates a maximum 3.95-mV potential across 0.305 m of a person’s chest, creating a 0.75-Hz electr
    15·1 answer
  • Suppose a net force of 7900 N is applied to slide a 950 kg crate across the floor. Compute the resulting acceleration of the cra
    9·1 answer
  • A car at a position 150 km [W] of Toronto travels to a position 400 km [W] of
    15·1 answer
  • Below are four statements about acceleration. Which statement is not correct? A Acceleration always involves changing speed. B C
    13·1 answer
  • HELP ME PLEASE
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!