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
alexdok [17]
3 years ago
13

An electric motor rotating a workshop grinding wheel at a rate of 1.31 ✕ 102 rev/min is switched off. Assume the wheel has a con

stant negative angular acceleration of magnitude 3.40 rad/s2. (a) How long does it take for the grinding wheel to stop? (b) Through how many radians has the wheel turned during the interval found in (a)?
Physics
1 answer:
antoniya [11.8K]3 years ago
6 0

(a) 4.03 s

The initial angular velocity of the wheel is

\omega_i = 1.31 \cdot 10^2 \frac{rev}{min} \cdot \frac{2\pi rad/rev}{60 s/min}=13.7 rad/s

The angular acceleration of the wheel is

\alpha = -3.40 rad/s^2

negative since it is a deceleration.

The angular acceleration can be also written as

\alpha = \frac{\omega_f - \omega_i}{t}

where

\omega_f = 0 is the final angular velocity (the wheel comes to a stop)

t is the time it takes for the wheel to stop

Solving for t, we find

t=\frac{\omega_f - \omega_i }{\alpha}=\frac{0-13.7 rad/s}{-3.40 rad/s^2}=4.03 s

(b) 27.6 rad

The angular displacement of the wheel in angular accelerated motion is given by

\theta= \omega_i t + \frac{1}{2}\alpha t^2

where we have

\omega_i=13.7 rad/s is the initial angular velocity

\alpha = -3.40 rad/s^2 is the angular acceleration

t = 4.03 s is the total time of the motion

Substituting numbers, we find

\theta= (13.7 rad/s)(4.03 s) + \frac{1}{2}(-3.40 rad/s^2)(4.03 s)^2=27.6 rad

You might be interested in
A sky diver, with parachute unopened, falls 625 m in 15.0 s. Then she opens her parachute and falls another 362 m in 139 s. What
Jobisdone [24]

Answer:

v_{avg} = 6.41 m/s

Explanation:

Average velocity is defined as the ratio of total displacement of the motion and total time taken in that motion

here we know that initially the sky diver drops without opening parachute by total displacement 625 m

then she open her parachute and drop another 362 m

so first it took time t = 15 s to drop without open parachute

then it took t = 139 s to drop next displacement

so here total displacement is given as

d = 625 m + 362 m

total time is given as

t = 15 s + 139 s

so average velocity is given as

v_{avg} = \frac{625 + 362}{15 + 139}

v_{avg} = 6.41 m/s

4 0
3 years ago
Which of the following describes an action-reaction pair?
Vlad [161]

Answer:

Explanation: LETTER A

8 0
2 years ago
Read 2 more answers
5. Which of these is necessary for electricity to flow?
CaHeK987 [17]

Answer:

the circuit must be closed

Explanation:

4 0
3 years ago
Read 2 more answers
The si unit of measurement is a way for scientists to?
Vera_Pavlovna [14]
Have a universal record base. Everyone is able to understand the data compiled since the same measurement systems are being used around the world. This is just to simplify all of the information.
7 0
3 years ago
Physics approach to study macromoelcues at nanoscales <br> in detail plx
erastova [34]

Answer:

Abstracto

Los ácidos nucleicos y las proteínas comprenden una red de biomacromoléculas que almacenan y transmiten información que sustenta la vida de la célula. El estudio de estos mecanismos es un campo llamado biología molecular. El desarrollo de esta ciencia siempre ha ido acompañado de avances técnicos que permiten romper barreras metodológicas para probar hipótesis novedosas. Entre los métodos disponibles para los biólogos moleculares, destacan cinco: electroforesis, secuenciación, clonación, transferencia y reacción en cadena de la polimerasa. Su impacto llega a la genética, la medicina y la biotecnología. Aquí, se revisan la relevancia histórica, los fundamentos técnicos y las tendencias actuales de estos cinco métodos esenciales. La revisión pretende ser útil tanto para estudiantes como para científicos profesionales que buscan adquirir conocimientos avanzados sobre el valor de estos métodos para investigar los mecanismos moleculares que sostienen la vida.

8 0
2 years ago
Other questions:
  • Why is glass a good substance for storing chemicals?
    7·1 answer
  • A machine is device that____.
    7·1 answer
  • A sample of the inert gas krypton has its pressure tripled. if the original volume is 12 l, what is the final volume in l
    10·1 answer
  • Starting from rest, a 5.00 kg steel sphere rolls down a frictionless ramp with a height of 4.00 m. What is the sphere's speed wh
    15·1 answer
  • An ideal monatomic gas expands from an initial pressure and volume of 32 atm and 1.0 L to a final volume of 4.0 L. The initial t
    10·1 answer
  • ________ Layer of the atmosphere where jets fly through and contains ozone layer
    10·1 answer
  • What piece of sports equipment is aerodynamic
    14·1 answer
  • Explain the importance of wearing your seatbelt using Newton’s laws and motion
    11·1 answer
  • What is center of mass?
    14·1 answer
  • PLESSSS HELP THIS IS FOR A TEST GRADE AND I NEVER LISTEN
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!