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
eimsori [14]
3 years ago
8

Starting from rest, a disk rotates about its central axis with constant angular acceleration. in 6.00 s, it rotates 44.5 rad. du

ring that time, what are the magnitudes of (a) the angular acceleration and (b) the average angular velocity? (c) what is the instantaneous angular velocity of the disk at the end of the 6.00 s? (d) with the angular acceleration unchanged, through what additional angle (rad) will the disk turn during the next 6.00 s?
Physics
1 answer:
Klio2033 [76]3 years ago
7 0

a. The disk starts at rest, so its angular displacement at time t is

\theta=\dfrac\alpha2t^2

It rotates 44.5 rad in this time, so we have

44.5\,\mathrm{rad}=\dfrac\alpha2(6.00\,\mathrm s)^2\implies\alpha=2.47\dfrac{\rm rad}{\mathrm s^2}

b. Since acceleration is constant, the average angular velocity is

\omega_{\rm avg}=\dfrac{\omega_f+\omega_i}2=\dfrac{\omega_f}2

where \omega_f is the angular velocity achieved after 6.00 s. The velocity of the disk at time t is

\omega=\alpha t

so we have

\omega_f=\left(2.47\dfrac{\rm rad}{\mathrm s^2}\right)(6.00\,\mathrm s)=14.8\dfrac{\rm rad}{\rm s}

making the average velocity

\omega_{\rm avg}=\dfrac{14.8\frac{\rm rad}{\rm s}}2=7.42\dfrac{\rm rad}{\rm s}

Another way to find the average velocity is to compute it directly via

\omega_{\rm avg}=\dfrac{\Delta\theta}{\Delta t}=\dfrac{44.5\,\rm rad}{6.00\,\rm s}=7.42\dfrac{\rm rad}{\rm s}

c. We already found this using the first method in part (b),

\omega=14.8\dfrac{\rm rad}{\rm s}

d. We already know

\theta=\dfrac\alpha2t^2

so this is just a matter of plugging in t=12.0\,\mathrm s. We get

\theta=179\,\mathrm{rad}

Or to make things slightly more interesting, we could have taken the end of the first 6.00 s interval to be the start of the next 6.00 s interval, so that

\theta=44.5\,\mathrm{rad}+\left(14.8\dfrac{\rm rad}{\rm s}\right)t+\dfrac\alpha2t^2

Then for t=6.00\,\rm s we would get the same \theta=179\,\rm rad.

You might be interested in
Which of the following is equal to Velocity change per second​
Mademuasel [1]

Acceleration

Explanation:

Acceleration is a physical quantity that expresses the change in the velocity of a body per unit of time.

  Acceleration = \frac{V - U }{T}

V is the initial velocity

U is the final velocity

T is the time

It is has a unit of m/s²

Learn more:

Acceleration brainly.com/question/3820012

#learnwithBrainly

8 0
2 years ago
A skateboarder is accelerating forward. How would his acceleration change if he had more mass?
exis [7]

Answer:

If the force remains the same, the acceleration would decrease

Explanation:

According to Newton's second law, the acceleration of an object is given by

a=\frac{F}{m}

where

F is the force applied to the object

m is the mass of the object

As we see from the formula, the acceleration a is inversely proportional to the mass, m. Therefore, if the force F remains constant, this means that if the mass of the skateboarder increases, then the acceleration will decrease.

4 0
3 years ago
An advantage of light microscopes compared to electron microscopes is that light microscopes _____.
ivolga24 [154]
<span>C is the correct answer. Electron microscopes require a vacuum to work, so living cells cannot be seen because they cannot respire. Light microscopes use a ray of visible light instead of a beam of electrons to magnify something so it can be seen by the naked eye. There are two different types of electron microscope: transmission (TEM) and scanning (SEM).</span>
5 0
2 years ago
Read 2 more answers
A researcher finds that blood alcohol levels cause Progressive damage the liver all of mice and his study were fed the same amou
Juli2301 [7.4K]

Answer:hmm

Explanation:

4 0
2 years ago
The table shows the changes in velocity for several different cars. Each change takes place over a 10-second interval. Which car
sesenic [268]
Car B, Car C, And Car E Are either speeding up or slowing down
6 0
3 years ago
Read 2 more answers
Other questions:
  • what is the resistance of a 12m long wire having radius( 2*10 to the power - 4) and resistivity (3.14*10 to the power - 8)ohmM
    7·1 answer
  • Why will a change in velocity have a greater affect on KE than a change in mass?
    9·2 answers
  • Two very large parallel sheets a distance d apart have their centers directly opposite each other. The sheets carry equal but op
    9·2 answers
  • A 65-N box rest on a perfectly smooth surface. The minimum force needed to start the box moving is
    15·1 answer
  • Regions around the nucleus where electrons are most likely to be found are called
    13·2 answers
  • A 0.40-μF capacitor is connected to a 5.0-V battery. How much charge is on each plate of the capacitor? Express your answer usin
    15·1 answer
  • The chicken's eggs are fertilized interally or externally
    6·1 answer
  • Suppose there is a sample of xenon in a rectangular container. The gas exerts a total force of 4.47 N perpendicular to one of th
    8·1 answer
  • Nighttime is the result of
    15·2 answers
  • B. On a separate sheet of paper, describe the different ways of generating electric power. ​
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!