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
IrinaK [193]
3 years ago
15

A wheel is rotating freely at angular speed 660 rev/min on a shaft whose rotational inertia is negligible. A second wheel, initi

ally at rest and with 5 times the rotational inertia of the first, is suddenly coupled to the same shaft. (a) What is the angular speed of the resultant combination of the shaft and two wheels? (b) What fraction of the original rotational kinetic energy is lost?
Physics
1 answer:
sweet-ann [11.9K]3 years ago
6 0

Answer:

(a)  110 rev/ min

(b) 5/6

Explanation:

As per the conservation of linear momentum,

L ( initial ) = L ( final )

I' ω' = ( I' + I'' ) ωf

I' is the rotational inertia of first wheel and I'' is the rotational inertia of second wheel which is at rest.

(a)

So,    ωf = I' ω' /  ( I' + I'' )

As I'' = 5I'

ωf = I' ω' /  ( I' + 5I' )

ωf = ω'/ 6

now we know ω' = 660 rev /  min

therefore    ωf = 660/6

                       = 110 rev/ min

(b)

Initial kinetic energy will be K'

K' = I'ω'² / 2

and final K.E. will be   K'' =  ( I' + I'' )ωf² / 2

                                   K'' = ( I' + 5I' ) (ω'/ 6)²/ 2

                                   K'' = 6I' ω'²/72

                                   K'' = I' ω'²/ 12

therefore the fraction lost is

                ΔK/K' = ( K' - K'' ) / K'

                           =  {( I'ω'² / 2) - (I' ω'²/ 12)} / ( I'ω'² / 2)

                            = 5/6

You might be interested in
What additional information do you need to prove ∆ABC ≅ ∆DEF by the SAS Postulate?
miv72 [106K]

Answer:

Option A

You need a Angle C congruent to angle F

Explanation:

EX) Side angle Side = sas

6 0
3 years ago
A cup of coffee is sitting on a table in a train that is moving with a constant velocity. The coefficient of static friction bet
Vikki [24]

Answer:

a = 2.94 m/s²

Explanation:

In order for the cup not to slip, the unbalanced force on cup must be equal to the frictional force:

Unbalanced Force = Frictional Force

ma = μR = μW

ma = μmg

a = μg

where,

a = maximum acceleration for the cup not to slip = ?

μ = coefficient of static friction = 0.3

g = acceleration due to gravity = 9.8 m/s²

Therefore,

a = (0.3)(9.8 m/s²)

<u>a = 2.94 m/s²</u>

3 0
3 years ago
b. What would the momentum be if the mass of the bowling ball were doubled and its velocity still was 3 m/s?​
umka2103 [35]

Answer:

Twice.

Explanation:

The momentum of an object is given by :

p = mv

Where

m is mass and v is the velocity

If the mass of the ball were doubled, m'=2m and v'=v=3 m/s

New momentum,

p'=m'v'

p'=2m × v

p'=2mv

or

p'=2p

So, the new momentum becomes twice the initial momentum.

6 0
2 years ago
If, while standing on the bank of a stream, you wished to spear a fish swimming in the water out in front of you, would you aim
Serggg [28]

Answer:

<em>a) below the observed position</em>

<em>b) directly at the observed position</em>

<em></em>

Explanation:

If I'm standing on the bank of a stream, and I wish to spear a fish swimming in the water out in front of me, I would aim below the observed fish to make a direct hit. This is because the phenomenon of refraction of light in water causes the light coming from the fish is refract away from the normal as it passes  into the air and into my eyes.

If I'm to zap the fish with a taser, I would aim directly at the observed fish because the laser (a form of concentrated light waves) will refract into the water, taking the same path the light from the fish took to get to my eyes.

3 0
3 years ago
Analyze how some insects are able to move around on the surface of a lake or pond
koban [17]
It is called surface tension it is the elastic personality of some liquids as they pull together to take up as little surface area as possible. the water molecules would rather stay together than be pulled apart<span />
3 0
3 years ago
Other questions:
  • Use the facts below to answer the question: Who reaches One-Eyed Willie’s pirate ship first?
    5·1 answer
  • Define wheel and axle in science terms
    9·1 answer
  • In a Rutherford scattering experiment a target nucleus has a diameter of 1.34×10-14 m. The incoming α particle has a mass of 6.6
    8·1 answer
  • When buyers will purchase exactly as much as sellers are willing to sell, what is the condition that has been reached?
    8·1 answer
  • In 1984 a team of german physicists synthesized a new element by smashing an iron-58 nucleus into a lead-208 target. if a neutro
    6·1 answer
  • A bullet is fired into the air at an angle of 45°. How far does it travel before it is 1,000 feet above the ground? (Assume that
    10·1 answer
  • A rock from the top of a hill is falling from rest.
    9·1 answer
  • An electrical appliances
    8·1 answer
  • Question is in the pic
    5·2 answers
  • describe the journey that light takes from the sun to your eye when you are looking at fish in a pond
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!