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
deff fn [24]
3 years ago
6

g initial angular velocity of 39.1 rad/s. It starts to slow down uniformly and comes to rest, making 76.8 revolutions during the

process. a) What is its angular acceleration (in rad/s2 )
Physics
1 answer:
MrRa [10]3 years ago
7 0

Answer:

Approximately -1.58\; \rm rad \cdot s^{-2}.

Explanation:

This question suggests that the rotation of this object slows down "uniformly". Therefore, the angular acceleration of this object should be constant and smaller than zero.

This question does not provide any information about the time required for the rotation of this object to come to a stop. In linear motions with a constant acceleration, there's an SUVAT equation that does not involve time:

v^2 - u^2 = 2\, a\, x,

where

  • v is the final velocity of the moving object,
  • u is the initial velocity of the moving object,
  • a is the (linear) acceleration of the moving object, and
  • x is the (linear) displacement of the object while its velocity changed from u to v.

The angular analogue of that equation will be:

(\omega(\text{final}))^2 - (\omega(\text{initial}))^2 = 2\, \alpha\, \theta, where

  • \omega(\text{final}) and \omega(\text{initial}) are the initial and final angular velocity of the rotating object,
  • \alpha is the angular acceleration of the moving object, and
  • \theta is the angular displacement of the object while its angular velocity changed from \omega(\text{initial}) to \omega(\text{final}).

For this object:

  • \omega(\text{final}) = 0\; \rm rad\cdot s^{-1}, whereas
  • \omega(\text{initial}) = 39.1\; \rm rad\cdot s^{-1}.

The question is asking for an angular acceleration with the unit \rm rad \cdot s^{-1}. However, the angular displacement from the question is described with the number of revolutions. Convert that to radians:

\begin{aligned}\theta &= 76.8\; \rm \text{revolution} \\ &= 76.8\;\text{revolution} \times 2\pi\; \rm rad \cdot \text{revolution}^{-1} \\ &= 153.6\pi\; \rm rad\end{aligned}.

Rearrange the equation (\omega(\text{final}))^2 - (\omega(\text{initial}))^2 = 2\, \alpha\, \theta and solve for \alpha:

\begin{aligned}\alpha &= \frac{(\omega(\text{final}))^2 - (\omega(\text{initial}))^2}{2\, \theta} \\ &= \frac{-\left(39.1\; \rm rad \cdot s^{-1}\right)^2}{2\times 153.6\pi\; \rm rad} \approx -1.58\; \rm rad \cdot s^{-1}\end{aligned}.

You might be interested in
Which data set has the smallest standard deviation?
hjlf

Answer:

B. 22,22,23,23,22,22,23

Explanation:

The standard deviation is a measure of dispersion or variability of a data set. In order to determine the data set that has the smallest standard deviation, we shall investigate on the ranges of the data sets given. The range of a data set is simply the difference between the maximum and minimum values in a data set. A data set that has a smaller range also has a smaller standard deviation.

From the alternatives given, the data set given by alternative B has the smallest range and consequently the smallest standard deviation.

The maximum value is 23 while the minimum is 22. The range is 1.

5 0
3 years ago
Calculate the number of electrons in a small, electrically neutral silver pin that has a mass of 7.1 g. Silver has 47 electrons
Assoli18 [71]

<u>Answer:</u> The number of electrons in given amount of silver are 1.87\times 10^{24}

<u>Explanation:</u>

To calculate the number of moles, we use the equation:

\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}

We are given:

Given mass of silver = 7.1 g

Molar mass of silver = 107.87 g/mol

Putting values in above equation, we get:

\text{Moles of silver}=\frac{7.1g}{107.87g/mol}=0.066mol

Number of electrons in 1 atom of silver = 47

According to mole concept:

1 mole of an element contains 6.022\times 10^{23} number of particles

So, 0.066 moles of silver will contain = -(0.066\times 47\times 6.022\times 10^{23})=1.87\times 10^{24} number of electrons

Hence, the number of electrons in given amount of silver are 1.87\times 10^{24}

7 0
3 years ago
The brakes on a 15,680 N car exert a stopping force of 640 N.
Murrr4er [49]

Answer:

1568 Kg is the answer

Explanation:

6 0
3 years ago
D the element in blue square has a full outer shell, due to it’s location on the periodic table, so it will not react with other
Juliette [100K]
The correct response that will be used to describe this particular element would be the third option, since all of the other options are incorrect and apply to different elements in their groups. The element is a metal and will react with a non metal.






5 0
3 years ago
You can only score 1 point when shooting a free throw. Group of answer choices True False
emmainna [20.7K]

Answer:

2 points

Explanation:

4 0
2 years ago
Read 2 more answers
Other questions:
  • What is a stack of membranes that packages chemicals
    9·1 answer
  • What location on earth experiences the most change the number of daylight hours?
    8·1 answer
  • A 6 kg bowling ball moves with a speed of 3 m/s. How fast does a 7 kg bowling ball need to move so that it has the same kinetic
    5·1 answer
  • A light, inextensible cord passes over a light, frictionless pulley with a radius of 15 cm. It has a(n) 14 kg mass on the left a
    15·2 answers
  • Which career is most concerned with the study of radioactive isotopes?
    5·1 answer
  • you and your friend each drive 70 miles you drive 60 miles/hour and your friend. drives 55 miles / hour how much sonner will you
    15·1 answer
  • What is the wavelength of a 1.28 x 10^17 Hz wave?
    5·1 answer
  • Change in v= 9.8 m/s2xt. The diagram shows a ball falling toward Earth in<br> a vacuum.
    8·2 answers
  • 2. What gravitational attraction does the moon have on the earth? (mass of earth is 6 x
    6·1 answer
  • There are two factors that limit how much he can bake in a week: He only wants to work for 40 hours a week and he only has one o
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!