A solid disk with a mass of 0.8 kg and a radius of 12cm is rotating at a rate of 2.6 rev/s. Another disk with half the mass and half the radius is dropped on top of the first disk. What is the new angular speed of both disks when they are rotating together?

Answers

Answer 1

Answer:

The new angular speed of both disks when they are rotating together is 2.311 revolutions per second.

Explanation:

This situation can be analyzed by the Principle of Conservation of Angular Momentum since there are no external forces and moments being exerted on the system, whose definition is presented below:

[tex]I_{o}\cdot \omega_{o} = I_{f}\cdot \omega_{f}[/tex] (1)

Where:

[tex]\omega_{o}[/tex], [tex]\omega_{f}[/tex] - Initial and final angular speeds, measured in revolutions per second.

[tex]I_{o}, I_{f}[/tex] - Initial and final moments of inertia, measured in kilograms per square meter.

The initial and final moments of inertia of the system are, respectively:

[tex]I_{o} = \frac{1}{2}\cdot m_{o}\cdot r_{o}^{2}[/tex] (2)

[tex]I_{f} = \frac{1}{2}\cdot \left[m_{o}\cdot r_{o}^{2}+\frac{1}{2}\cdot m_{o}\cdot \left(\frac{1}{2}\cdot r_{o} \right)^{2}\right][/tex]

[tex]I_{f} = \frac{1}{2}\cdot m_{o}\cdot r_{o}^{2}+\frac{1}{16}\cdot m_{o}\cdot r_{o}^{2}[/tex]

[tex]I_{f} = \frac{9}{16}\cdot m_{o}\cdot r_{o}^{2}[/tex] (3)

By applying (2) and (3) in (1), we obtain the following expression:

[tex]\frac{1}{2}\cdot m_{o}\cdot r_{o}^{2}\cdot \omega_{o} = \frac{9}{16}\cdot m_{o}\cdot r_{o}^{2}\cdot \omega_{f}[/tex]

[tex]\frac{1}{2}\cdot \omega_{o} = \frac{9}{16}\cdot \omega_{f}[/tex]

[tex]\omega_{f} = \frac{8}{9}\cdot \omega_{o}[/tex] (4)

If we know that [tex]\omega_{o} = 2.6\,\frac{rev}{s}[/tex], then the new angular speed of both disks when they are rotating together is:

[tex]\omega_{f} = \frac{8}{9}\cdot \left(2.6\,\frac{rev}{s} \right)[/tex]

[tex]\omega_{f} = 2.311\,\frac{rev}{s}[/tex]

The new angular speed of both disks when they are rotating together is 2.311 revolutions per second.


Related Questions

(6.9 * 10-6)(770 * 102)

Answers

Answer:

4948020

Explanation:

(6.9*10-6)(770*102)

Multiply  6.9  by  10 .

( 69 − 6 ) ( 770 ⋅ 102 )

Subtract  6  from  69 .

63 ( 770 ⋅ 102 )

Multiply  770  by 102 .

63 ⋅ 78540

Multiply  63  by  78540 .

4948020

What is the Potential Energy of a roller coaster if it has a velocity of 35 m/s and a mass of 2000 kg and is at a height of 200 m? Please answer fast

A.) 137,200,000 J
B.) 12,005,000 J
C.) 3,920,000 J
D.) 1,400,000 J

Answers

Answer:

C

Explanation:

It cant be A or D, meaning your left with B and C. there cant be an answer in the 1000's place eather

Which substance may lower air temperatures after a volcanic eruption?

lava
sulfur dioxide
carbon dioxide
water vapor

Answers

The awnser is sulfur dioxide.

The gas that is responsible for lowering the temperature is sulfur dioxide gas.

A volcanic eruption refers to the sudden escape of lava and gases from the earth's core. It usually occurs at a very high temperature. The solidification of the volcano leads to rock formation.

During a volcanic eruption, the gas that is responsible for lowering the temperature is sulfur dioxide gas.

Learn more: https://brainly.com/question/1622004

Angelica inhaled deeply into a plastic cup. Why did the cup collapse?

Answers

Answer:

Air vacuum.

Explanation:

Air may seem like nothing, but there are tons of molecules in it. Air takes up space. When Angelica inhales, the air rushes into into and escapes the cup. Since theres no air anymore, the cup collapses because thereis no more space in it. She removes the air from the cup and it creates a vacuum inside, sucking the sides of the cup in.

1. According to paragraph 3 in the text, MOST of the electromagnetic waves from
the sun that reach Earth are: *
O A. microwaves, x rays and visible light
O B. radio waves, infrared waves and visible light
O C. infrared waves, visible light and ultra-violet radiation
D. gamma rays, ultra-violet radiation and microwaves

Answers

Answer:

Most of the EM waves from the sun that reach Earth are infrared waves, visible light, and UV radiation.

Explanation:

I hope this helps! Have a good day!

characteristics of projectile motion.

Answers

Answer:

Objects experiencing projectile motion have a constant velocity in the horizontal direction and a constantly changing velocity in the vertical direction. The trajectory resulting from this combination always has the shape of a parabola.

Explanation:

Answer:

Projectile motion is made up two independent motions: Uniform motion at constant velocity in the horizontal direction and Free-fall motion in the vertical direction. Although the horizontal and vertical motions of a projectile are independent, they are connected through the time that the object is the the air.

A radioactive nuclide of atomic number Z emits an alpha particle and the daughter nucleus then emits a beta particle. What is the atomic number of resulting nuclide?
A) Z-1
B) Z+1
C) Z-2
D) Z-3

Answers

Answer:

A) Z-1

Explanation:

when a radioactive element of atomic number Z emits an alpha particle, the mass of the new nucleus decreases by 2, i.e the new atomic number of the element = ( Z- 2).

Also, when the daughter nucleus emits a beta particle, the new nucleus increases by 1,  that is the new atomic number of the element = (Z + 1).

Thus, the atomic number of resulting nuclide = Z ( - 2) + ( + 1).

                                                                           = Z - 2 + 1

                                                                           = Z - 1

Therefore, the atomic number of resulting nuclide is Z - 1

Which factor listed below has the greatest effect on the period of a pendulum?

a
Mass of the pendulum
b
Angle of the pendulum
c
Length of the string
d
Amplitude of the oscillations

Answers

Answer:

C

Explanation:

equation for pendulum period is

[tex]\mathrm{T}=2 \pi \sqrt{\frac{\mathrm{L}}{\mathrm{g}}}[/tex]

and it depends only on its length (and gravity which is not on the list of answers)

10. A boy weighs 475 N. What is his mass? (acceleration due to gravity on Earth is 9.8m/s2 = g)


Answers

Answer: mass = 48.47 kg.

Explanation:

Formula : Weight = mg  , where m = mass of body , g= acceleration due to gravity .

Given: Weight  = 475 N

[tex]g= 9.8\ m/s^2[/tex]

Substitute all values in formula ,  we get

[tex]475= m \times9.8\\\\\Rightarrow\ m = \dfrac{475}{9.8}\\\\\Rightarrow\ m \approx 48.47\ kg[/tex]

Hence, his mass = 48.47 kg.

Which is an example of balanced forces acting on an object?
a kangaroo jumping
a car turning a corner
a cyclist slowing down
a leaf lying on the grass

Answers

Answer:

a leaf lying on the grass

Explanation:

there is no movement (unbalanced forces) acting on the leaf so that's why it is still lying down and not changing its motion

When the force acting on a body is zero is called balanced force. Option D is correct.

What is balanced force?

Force is defined as a push or pull of an object. Balanced forces are equal and opposite in direction. In balanced forces, there is no change in motion. In balanced force, the object is in equilibrium( i.e : the object is not moving with change in speed).

Unbalanced force is a force that can change the state of uniform motion or the rest of the body. If an object is moving with change in speed, it is said to be unbalanced.

From the given, some of them like kangaroo jumping, car turning a corner, cyclist slowing down shows motion except leaf lying on the grass. The leaf lying on the grass does not show any movement or motion, it is an example of balanced force.

Hence, the correct option is D) Leaf lying on the grass.

Learn more about Balanced and Unbalanced forces:

https://brainly.com/question/29372261

#SPJ3

James is planning on registering for a course in electrical engineering which of the following sub disciplines could he opt for instrumentation engineering prosthetics plant design or signal processing

Answers

Answer:

Instrmentation engineering

Explanation:

Hope this helps!

g A wave on a string has a speed of 13.3 m/s and a period of 0.3 s. What is the frequency of the wave

Answers

Answer:

3.33 Hz

Explanation:

The first step is to calculate the wavelength

= speed × period

= 13.3 × 0.3

= 3.99

Therefore the frequency of the wave can be calculated as follows

= speed/wavelength

= 13.3/3.99

= 3.33 Hz

What type of electromagnetic wave is a TV remote and a cloud

Answers

Answer: Kids learn about the types of electromagnetic waves in the science of physics ... Microwaves are useful in communication because they can penetrate clouds, ... These are the infrared waves that are used in your TV remote to change channels

Explanation:

Details
A 70 kg student rides the Gravitron at a carnival. The
Gravitron has a radius of 2.75 meters. The student feels
a centripetal force of 2100 N. How fast is the Gravitron
spinning?

Answers

I believe the answer your looking for is A

Answer:

1400 math quiz

Explanation:

40s n shorty's

why do feet smell and noses run?

Answers

Answer:

Nose has mucous glands with hairs which helps the body in trapping pollutants and infectants from entering inside the body. On the other hand,our feet is composed of millions of sweat pores when dirt and other things accumulate,it smells because of sweat mixed with the dirt and other dirty things of the ground.

Explanation:

Hope this helps

Help me please..

When the slope of a velocity vs. time graph is negative and constant,
what type of motion is occurring?

A) No motion

B) Constant speed

C) Acceleration

D) Constant Velocity

E) Going in circles

Answers

The answer is Acceleration!

I
2800000 kg
Fig. 2.1
The total mass of the rocket and its full load of fuel is 2.8 106 kg. The constant force provided by
the rocket's motors is 3.2 x 107N.
32000000 N.
(a) Calculate
(i) the total weight of the rocket and the fuel.
weight =

Answers

Answer:

W = 27468000 [N] or 27.47 [kN]

Explanation:

The weight of a body is defined as the product of mass by gravitational acceleration.

[tex]W = m*g[/tex]

where:

W = weight of the rocket with fuel [kg]

m = mass = 2800000 [kg]

g = gravity acceleration = 9.81 [m/s²]

Now we can solve:

[tex]W = 2800000*9.81\\W = 27468000 [N][/tex]

A string of length 10.0 m is tied between two posts and plucked. This sends a wave down the string moving at a speed of 130 m/s with a frequency of 215 Hz. How many complete wavelengths of this wave will fit on the string?

Answers

Answer:

16.

Explanation:

In any wave, by definition, there exists a fixed relationship between the speed v, the frequency f , and the wavelength λ, as follows:

        [tex]v = \lambda * f (1)[/tex]

In our case, v = 130 m/s and f= 215 Hz, so solving for λ in (1), we get:

        [tex]\lambda = \frac{v}{f} = \frac{130m/s}{215 hz} = 0.61 m (2)[/tex]

In order to know how many wavelengths of this wave will fit on the string, we need just do divide the length of the string (10.0 m) over one single wavelength, as follows:

       [tex]n = \frac{L}{\lambda} = \frac{10.0m}{0.61m} = 16.4 (3)[/tex]

Since we need to take the integer value from this expression, the number of complete wavelengths that will fit on this string is just 16.

a wandering dog walks 1 km due east, 1 km due south, then runs 2 km due west. the magnitude of the dogs displacement is closest to
a. 0 km
b. 1.4 km
c. 3.4 km
d. 4.0 km​

Answers

Answer:

b) 1.4km

Explanation:

A tennis ball is traveling at 50 m/s and has a kinetic energy of 75J. Calculate the mass of the tennis ball.

Answers

couldn’t fit all of it , but here luv

WGVU-AM is a radio station that serves the Grand Rapids, Michigan area. The main broadcast frequency is 1480kHz. At a certain distance from the radio station transmitter, the magnitude of the magnetic field of the electromagnetic wave is 3.0x10^-11T.
a. Calculate the wavelength
b. What is the angular velocity?
c. Find the wave number of the wave.
d. What is the amplitude of the electric field at this distance from the transmitter?

Answers

Answer:

a

  [tex]\lambda = 202.7 \ m[/tex]

b

  [tex]w = 9.3 *10^{6} \ rad/s[/tex]

c

  [tex]k = 0.031 m^{-1}[/tex]

d

  [tex]E_{max} = 9.0 *10^{-3} \ V/m[/tex]

Explanation:

From the question we are told that  

       The frequency of the radio station is  [tex]f= 1480 \ kHz = 1480 *10^{3}\ Hz[/tex]

         The magnitude of the magnetic field is  [tex]B = 3.0* 10^{-11} \ T[/tex]

Generally the wavelength is mathematically represented as

          [tex]\lambda = \frac{c}{f}[/tex]

Here c is the speed of light with value  [tex]c = 3.0 *10^{8} \ m/s[/tex]

So

        [tex]\lambda = \frac{3.0 *10^{8}}{ 1480 *10^{3}}[/tex]

=>      [tex]\lambda = 202.7 \ m[/tex]

Generally the angular frequency is mathematically represented as

       [tex]w = 2 \pi * f[/tex]

=>   [tex]w = 2 * 3.142 * 1480 *10^{3}[/tex]

=>   [tex]w = 9.3 *10^{6} \ rad/s[/tex]

Generally the wave number is mathematically represented as        

=>      [tex]k = \frac{2 \pi }{\lambda}[/tex]

=>      [tex]k = \frac{2 * 3.142 }{ 202.7}[/tex]

=>      [tex]k = 0.031 m^{-1}[/tex]

Generally the amplitude of the electric field at this distance from the transmitter is mathematically represented as

         [tex]E_{max} = c * B[/tex]

=>      [tex]E_{max} = 3.0 *10^{8} * 3.0* 10^{-11}[/tex]

=>      [tex]E_{max} = 9.0 *10^{-3} \ V/m[/tex]

Help me please..

Velocity is defined as a
and a?

A) speed, direction

B) change, direction

C) speed, acceleration

D) change, acceleration

Answers

it’s A speed in a given direction

Answer:

Speed and direction.....

When will the human brain be fully developed?
A. By age 15
B. The early 20s
C. The late 20s
D. The 30s

Answers

Answer:

C.

Explanation:

The human brain isn't fully developed until 25 years of age. Everything is there except for the frontal cortex, which is the last thing to mature. An immature frontal cortex explains the spectrum of teenage behaviors: it's what makes adolescents adolescent, says Sapolsky.

Answer:

25!

Explanation:

Find the current if 55 C of charge pass a particular point in a circuit in 5 seconds.

Answers

Answer:

The current is 11 Amperes

Explanation:

Electric Current

The electric current is defined as a stream of charged particles that move through a conductive path.

The current intensity can be calculated as:

[tex]\displaystyle I=\frac{Q}{t}[/tex]

Where:

Q = Electric charge

t   = Time taken by the charge to move through the conductor

The current intensity is often measured in Amperes.

The charge passing through a point in a circuit is Q= 55 c during t=5 seconds, thus the current intensity is:

[tex]\displaystyle I=\frac{55}{5}[/tex]

I = 11 Amp

The current is 11 Amperes

A force of 64 N gives an object an acceleration of 23.53 m/s^2. What is the mass of the object?
A-2.00 kg
B-1505 kg
C-2.72 kg
D-736 kg

Answers

D is the right answer for this I think

Lab - Wave Properties in a Spring

11-05
The wave characteristics you will observe in this lab are common to all waves (water, light, sound,
etc.). Use your prior knowledge and the book to fill in the following blanks, then go in the hall and
perform the lab.
A wave is a disturbance that moves through (propagates) through empty space or through a
_____________. There are two types of waves. A _____________________ wave requires
matter to travel. List some examples of this type:
A _____________________ wave does not require a medium. Examples include:
In order to start and transmit a mechanical wave, a source of _____________ and an
_______________ medium are required. A single disturbance is referred to as a
_______________, and a series of disturbances is a wave __________.
The questions in bold are those you should observe directly. Others will be answered using the book.
A. TYPES OF MECHANICAL WAVES: In the hall, stretch the slinky on the floor until it is
stretched (but still loose). Practice sending single pulses down the slinky by popping your wrist
from the center to the side and back to the center. Then send a continuous wave train along as
your partner holds the other end still. A piece of ribbon should be tied to one coil. Watch the
motion of this ribbon (representing a particle) as the wave travels through the spring.
In this type of wave, the particles move (perpendicular, parallel)
to the direction the wave travels. This type of wave is called a __________________ wave.
Its pulses are called ________________ and ________________.
Now send a pulse by quickly pushing the spring forward and pulling
it back, as shown. This type of wave is called _______________. Watch the motion of the ribbon.
In this type, the particles move _____________ to the direction the wave travels. Its pulses
are called _____________ and _____________. Label each.
Note that all waves transfer _____________ without transferring _______________. In
mechanical waves, particles of the medium vibrate back and forth in simple harmonic motion while
the disturbance (or _____________) moves from one place to another.
B. WAVE SPEED
Send a large pulse, followed by a small one. Does one pulse catch up to the other? ______
(Hint: The person who sends these waves should watch how the waves look when they return. Make
sure that both pulses are large enough initially to make it back to the sender!) The size of the
pulse is called the __________________ of the wave. Did the size affect the speed? ______
Generate a single transverse pulse in the slinky, keeping the stretch constant. Using a stopwatch,
time the journey of the pulse from one end to the other and back again. Take the average of
several trials. _________
Without changing your positions on the floor (therefore keeping the _____________ the pulse
travels the same), pull the slinky tighter using only about 3/4 of the coils. This makes a completely
different medium through which the pulse will travel. Time the journey as before. ___________
Does the kind of medium affect the speed of the pulse? ___________
Lab – Wave Properties in a Spring ____________________
PHYSICSFundamentals
© 2004, GPB
11-06
C. WAVELENGTH AND FREQUENCY
Shake the slinky back and forth steadily to send a
transverse wave train while your partner holds the other end still. On the diagram, label wavelength
(- Greek letter lambda). The frequency of the wave depends on how fast you shake the slinky.
Shake it regularly but slowly, then regularly but rapidly.
Higher frequency waves are generated by shaking the spring (slowly, rapidly). High frequency
waves have (short, long) wavelengths, and low frequency waves have __________.
The speed of a wave in any medium is equal to the _______________ of the wave X
________________. This wave equation ___________________ shows that f and  are
______________ proportional. Write the units for each of the variables in this equation.

Answers

The exercise involves filling in the gaps with the possible wave

properties that can be obtained from a spring.

How is the Wave Properties in a Spring Lab exercise correctly completed?

The correctly completed exercise is presented as follows;

A wave is a disturbance that moves through a medium. There are two

types of waves. A mechanical wave requires matter to travel. List some

examples of this type: sound wave, water wave, spring waves.

A electromagnetic wave does not require a medium. Examples include: Light waves

In order to start and transmit a mechanical wave, a source of

disturbance and a physical medium are required. A single disturbance is

referred to as a pulse, and a series of disturbance is a wave train.

This type of wave is called transverse wave. Its pulses are called crest

and troughs.

Now send a pulse by quickly pushing the spring forward and pulling it

back, as shown. This type of wave is called longitudinal wave. Watch the

motion of the ribbon. In this type, the particles move parallel to the

direction the wave travels. Its pulses are called compression and

rarefactions. Note that all waves transfer energy without transferring

matter. In mechanical waves, particle of the medium vibrate back and

forth in simple harmonic motion while the disturbance (or energy)

moves from one place to another.

B. Wave speed

Does the pulse catch up to the other? yes. The size of the pulse is called

the amplitude of the wave.

Did the size of the pulse affect the speed? No.

The average time wave it takes the wave to travel

Without changing your positions therefore keeping the distance the

pulse travels the same), pull the slinky tighter using only about 3/4 of

coils. This makes a completely different medium through which the

pulse will travel. Time the journey as before time record. Does the kind

of medium affect the speed of the pulse? Yes

C. Wavelength and Frequency

High frequency waves have short wavelengths and low frequency waves

have long wavelengths.

The speed of a wave in any medium is equal to the frequency of the wave × the wavelength. This wave equation [tex]\underline{f = \dfrac{v}{\lambda } }[/tex] shows that f and λ are

inversely proportional. The units of the variables are;

Units of the frequency, f is hertz unit HzUnits of the velocity, v, is m/sUnits of the wavelength, λ, is meters (m)

Learn more about waves here:

https://brainly.com/question/14118172

A particular engine has a power output of 2 kW and an efficiency of 27%. If the engine expels 9085 J of thermal energy in each cycle, find the heat absorbed in each cycle. Answer in units of J.

Answers

Answer:

12445 J

Explanation:

Given that

Power output, P = 5 kW

efficiency of the engine, e = 27% = 0.27

Thermal energy expelled, Q(c) = 9085 J

Heat absorbed, Q(h) = ?

Using the formula

e = W/Q(h)

e = [Q(h) - Q(c)] / Q(h)

e = 1 - Q(c)/Q(h)

Now, substituting the values into the formula, we have

0.27 = 1 - 9085/Q(h)

9085/Q(h) = 1 - 0.27

9085/Q(h) = 0.73

Q(h) = 9085 / 0.73

Q(h) = 12445 J

Thus, the heat absorbed is 12445 J

If the social distancing length between two students is doubled from two metered to four meters, does the gravitational force between the two students increase or decrease?

Explain your reasoning!

Answers

Answer:

the gravitational force decreases

20 pts.





Which of the following statements is true?
O Electromagnets use electrlcity and magnets.
O Magnetic fields are strongest around the poles of a magnet.
O The south pole of a magnet will repel the south pole of another magnet.
O all of the above

Answers

Answer:

all are true so d is right

Explanation:

Electromagnets use electrlcity and magnets is true.

Magnetic fields are strongest around the poles of a magnet is true.

The south pole of a magnet will repel the south pole of another magnet is true

and since all of them is true the answer is d all of the above

The average speed of a car that drives 140 kilometers in 2 hours

Answers

Answer:

240 kilometer

Explanation:

ur just mutipling the number by 2

Your average speed was 70.0 Kilometers per hour (km/h)

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