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
mars1129 [50]
3 years ago
6

A disk shaped grindstone of mass 3.0 kg and radius 8 cm is spinning at 600 rpm. After the power is shut off the frictional torqu

e brings the grindstone to rest in 10 s. What is the number of revolutions of the grindstone after the power is shut off?
Physics
1 answer:
seropon [69]3 years ago
7 0

Answer:

\theta=50\ revolution

Explanation:

It is given that,

Mass of the grindstone, m = 3 kg

Radius of the grindstone, r = 8 cm = 0.08 m

Initial speed of the grindstone, \omega_i=600\ rpm=62.83\ rad/s

Finally it shuts off, \omega_f=0

Time taken, t = 10 s

Let \alpha is the angular acceleration of the grindstone. Using the formula of rotational kinematics as :

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

\alpha =\dfrac{0-62.83}{10}

\alpha =-6.283\ rad/s^2

Let \theta is the number of revolutions of the grindstone after the power is shut off. Now using the third equation of rotational kinematics as :

\omega_f^2-\omega_i^2=2\alpha \theta

\theta=\dfrac{\omega_f^2-\omega_i^2}{2\alpha }

\theta=\dfrac{-62.83^2}{2\times -6.283}

\theta=314.15\ radian

\theta=49.99\ revolution

or

\theta=50\ revolution

So, the number of revolutions of the grindstone after the power is shut off is 50.

You might be interested in
How does technology make sustainability more difficult?
alexgriva [62]
Well sustainability means the ability of future generations to meet their own needs so technology gets in the way of things getting done and is distracting in some ways. i hope this helps!
4 0
3 years ago
Read 2 more answers
Which statement describes how nuclear power generation systems work?
galben [10]

Answer:

c- heat for electricity generation process comes from nuclear fission

Explanation:

nuclear fission is splitting of atoms to release energy held at nucleus of atoms

4 0
2 years ago
A 60.0-kg skater begins a spin with an angular speed of 6.0 rad/s. By changing the position of her arms, the skater decreases he
juin [17]

The skater's final angular speed is equal to 12 rad/s.

When implemented to angular momentum, the regulation of conservation means that the momentum of a rotating item is no longer exchanged until some form of external torque is carried out. Torque, in this sense, can check with any outside pressure that acts upon the object for the purpose to twist or rotate.

The law of conservation of angular momentum states that once no external torque acts on an item, no trade of angular momentum will occur. The angular momentum of a machine is conserved as long as there may be no net external torque performing on the machine.

In angular kinematics, the conservation of angular momentum refers back to the tendency of a device to keep its rotational momentum inside the absence of outside torque. For a round orbit, the system for angular momentum is (mass) ×(pace) ×(radius of the circle): (angular momentum) = m × v × r.

Learn more about angular momentum here brainly.com/question/7538238

#SPJ4

7 0
1 year ago
Two charges, -20 C and +4.7 C, are fixed in place and separated by 3.0 m. a. At what spot along a line through the charges is th
Pani-rosa [81]

The zero net electric field point is at a point that is 0.98 m away from 4.7C charge.If a 14C charge is placed at this point then, force acted on the charge placed at this point is equal to zero.

Explanation:

Let at A both net electric field is zero then

At A ,E1=E2

E1=k*Iq1I / (d+x)^2

E2=k*Iq2I /x^2

Equating both

6 0
3 years ago
Discuss how a photon (aka the light particle) can be affected by gravity despite being massless.
Over [174]

Explanation:

Light is clearly affected by gravity, just think about a black hole, but light supposedly has no mass and gravity only affects objects with mass. On the other hand, if light does have mass then doesn't mass become infinitely larger the closer to the speed of light an object travels.

4 0
3 years ago
Other questions:
  • A crane performs 1820 J of work by lifting an object 35 meters. How much force did the crane exert?
    8·1 answer
  • A 75.0 kg ladder that is 3.00 m in length is placed against a wall at an angle theta. The center of gravity of the ladder is at
    9·1 answer
  • What is the mechanical advantage supplied by a 1000 N object lifted using 250 N of force
    6·1 answer
  • Which answer best describes thermal energy?
    15·1 answer
  • According to the kinetic theory of gas particles, when do gas particles have some type of force between them?
    7·2 answers
  • Two round rods, one steel andthe other copper, are joined end to end. Each rod is 0.750 mlong and 1.50 cmin diameter. The combin
    13·1 answer
  • An electromagnet is a ? with a ? core
    9·2 answers
  • Two point charges, A and B, are separated by a distance of 19.0 cm . The magnitude of the charge on A is twice that of the charg
    7·1 answer
  • 1. Which of the following is true about sound waves?
    13·1 answer
  • A 45000 watt crane operating at full power lifts a 2100 kg object vertically for 17.4 seconds. How high has the crane lifted the
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!