A horizontal platform in the shape of a circular disk rotates on a frictionless bearing about a vertical axle through the center of the disk. The platform has a mass of 150 kg, a radius of 2.0 m, and a rotational inertia of 300 kg·m2 about the axis of rotation. A 60 kg student walks slowly from the rim of the platform toward the center. If the angular speed of the system is 1.4 rad/s when the student starts at the rim, what is the angular speed when she is 0.70 m from the center?

Answers

Answer 1

Answer: [tex]2.29\ rad/s[/tex]

Explanation:

Given

Mass of Platform M=150 kg

the radius of Platform R=2 m

Moment of inertia of Platform [tex]I=300\ kg.m^2[/tex]

Mass of student [tex]m=60\ kg[/tex]

The initial angular speed of the student is [tex]\omega _1=1.4\ rad/s[/tex]

Initially, the moment of inertia of platform and student is

[tex]I_1=\dfrac{1}{2}MR^2+mR^2\\\\I_1=300+60\times 4=540\ kg.m^2[/tex]

The final moment of inertia

[tex]I_2=\dfrac{1}{2}MR^2+mr^2\\\\I_2=300+60\times 0.7^2=329.4\ kg.m^2[/tex]

Conserving angular momentum

[tex]I_1\omega_1=I_2\omega _2\\\\540\times 1.4=329.4\times \omega_2\\\\\omega_2=\dfrac{756}{329.4}=2.29\ rad/s[/tex]


Related Questions

A wave has a frequency of 60 Hz and a wavelength of 1.7 meters. What is the speed of this wave? equation, substitution

Answers

Answer:

v = 102 m/s

Explanation:

Given that,

The frequency of a wave, f = 60 Hz

Wavelength = 1.7 m

We need to find the speed of this wave. The formula for the speed of a wave is given by

[tex]v=f\lambda[/tex]

Substitute all the values,

[tex]v=60\times 1.7\\\\v=102\ m/s[/tex]

So, the speed of the wave is equal to 102 m/s.

Why would you have trouble breathing at high altitudes?
A. it is colder at the top of a mountain
B. the oxygen molecules are spread farther apart
C. the oxygen molecules are closer together

Answers

Answer:

A. It is colder at the top of a mountain

Explanation:

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Answer:

Velocidad.

Explanation:

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Por ende, la opción correcta es: Velocidad.

All waves change speed when they enter a new medium, but they don't always bend. When does bending occur?

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Bending occurs when one side of the wave enters the new medium before the other side of the wave. ... The bending occurs because the two sides of the wave are traveling at different speeds.

The half-life of technetium-99 is 6 hours.How much of a 100 milligram sample of
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O 12.5 mg
O 6.25 mg
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Answers

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explain why the rate of diffusion of a gas decreases with decrease in temperature​

Answers

Temperature: Higher temperatures increase the energy and therefore the movement of the molecules, increasing the rate of diffusion. Lower temperatures decrease the energy of the molecules, thus decreasing the rate of diffusion. Solvent density: As the density of a solvent increases, the rate of diffusion decreases.

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Question 5 of 10
What are two things that happen when a home computer scanner uses
electromagnetic waves?
A. Red light shines on patterns of black and white, recording the
pattern of reflected light.
B. Objects are exposed to X-rays, which either pass through or are
absorbed by the objects.
C. A silicon chip releases electrons by the photoelectric effect,
producing an image.
D. A charge-coupled device captures visible light that is reflected off
an object

Answers

Answer: B. Objects are exposed to X-rays, which either pass through or are

absorbed by the objects.

C. A silicon chip releases electrons by the photoelectric effect,

producing an image.

Explanation:

answer is bbbbbbbbbb

____ 2. When an object is heated to the point that it glows, the process is called incandescence. ____________________

Answers

Answer:

True

Explanation:

Incandescence material are those which glow on being heated above a particular point.  For example an incandescence bulb which has a filament. when the filament is heated it starts to glow.

The least energy efficient type of electronic lights typically used in residential buildings are usually called incandescent lamps. Although ineffective, incandescent lamps provide a variety of important advantages, they are inexpensive to purchase, turn on instantly and are available in a wide range of sizes and shapes.

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Showing respect to others
B. Working well with others
c.
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D
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Answers

Answer:

The answer is all of the above

Explanation:

Answer:

D

Explanation:

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Maybe stainless steel :)

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Answer:

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Explanation:

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Answer:

Well my good friend the other person did not give U a good answer, it is actually the third one

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A 10,000-watt radio station transmits at 535 kHz.


Calculate the energy of a single photon at the transmitted frequency.


A)3.55 × 10-28 J/photon

B)3.55 × 10-31 J/photon

C)6.63 × 10-30 J/photon

Answers

Answer: A

Explanation: E=hv, E-energy, h-Planck constant, v-frequency
E=6.63×10^(-34)*535*10^3=3.55*10^(-28) (J) Photon energydoesn't depend on the power of radio station

The energy of a single photon at the transmitted frequency is

A)3.55 × 10^(-28)J/photon

What is the energy of a single photon?

Energy of photon can be rewritten as

E=hv,

Where, h is planck's constant  

λ is the wavelength of photon  

Where f is the frequency of photon  

Thus, the energy of a single photon at the transmitted frequency obtained by using the formula, Energy (E) is equal to Planck's constant (h) times the frequency.

E=6.63×10^(-34)× 535×10^3

E =3.55 × 10^(-28) (J)

Photon energy doesn't depend on the power of radio station

Learn more about the Energy here;

https://brainly.com/question/3838760

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A car goes from 0 m/s to 13 m/s in 10 seconds. What is the
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Answers

V initial = 0 m/s
V final = 13 m/s
Time = 10 s
Vf - Vi / T =
13-0/10 =
1.3 m/s^2

Answer:

V initial = 0 m/s

V final = 13 m/s

Time = 10 s

Vf - Vi / T =

13-0/10 =

1.3 m/s^2

Explanation:

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Answers

Answer:

v = 8.12 m/s

Explanation:

The centripetal acceleration of the yo-yo is given by the following formula:

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where,

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Therefore, using the given values in the formula, we get:

[tex]v = \sqrt{(200\ m/^2)(0.33\ m)}[/tex]

v = 8.12 m/s

SE UM CORPO ELETRICAMENTE NEUTRO É CARREGADO COM PROTONS, entao afirmamos; a) fica carregado negativamente b) fica carregado só com cargas positivas c) fica carregado positivamente d) fica com excesso de eletrons e) continua eletricamente neutro

Answers

Answer:

c) It gets positively charged

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Answers

Answer:

The answers to your questions are given below

Explanation:

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E => is the energy

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f => is the frequency

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Answers

Answer:

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Explanation:

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Answers

Answer:

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Explanation:

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Answers

Answer:

3rd Harmonic Frequency created by tuba is equal to [tex]87.375[/tex] hertz

Explanation:

Given -

4th Harmonic frequency created by tuba is equal to [tex]116.5[/tex] hertz

1st Harmonic Frequency created by tuba is equal to [tex]\frac{116.5}{4}[/tex] hertz

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87.375 Acellus

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Answer:

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Answer:

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