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
if you crash your car how could you decrease the damage to you or the car using the concept of impulse
kotykmax [81]

Explanation:

Crumple zones are sections in cars that are designed to crumple up when the car encounters a collision. Crumple zones minimize the effect of the force in an automobile collision in two ways. By crumpling, the car is less likely to rebound upon impact, thus minimizing the momentum change and the impulse.

3 0
3 years ago
5. How does a jack make changing a tire easier?
strojnjashka [21]

Answer: An jack makes changing a tire easier because it lifts up the car to get the tire off of the ground.

Explanation:

4 0
3 years ago
A cylinder of compressed gas has a pressure of 488.2 kPa. The next day the cylinder of gas has a
Luda [366]

Answer:

20 °C

Explanation:

Ideal gas law:

PV = nRT

Rearranging:

P / T = nR / V

Since n, R, and V are constant:

P₁ / T₁ = P₂ / T₂

488.2 kPa / T = 468 kPa / 281.15 K

T = 293.29 K

T = 20.1 °C

Rounded, the temperature was 20 °C.

6 0
3 years ago
A comet is cruising through the solar system at a speed of 50,000 kilometers per hour foe 4 hours time. What is the total distan
Triss [41]

Answer:

<em>The distance covered by comet is </em>200,000 km

Explanation:

Speed is defined as the rate of change of distance with time. It is given by the equation speed= \bold{\frac{distance}{time}}

Thus distance= speed*time

In this problem it is given that speed of comet= \frac{50,000km}{hr}

time travelled by the comet= 4 hours

Thus distance= speed*time

                            = 500000*4

                            = \bold{200,000km}

5 0
3 years ago
Which statement best explains how weight management through exercise can be a physiological mechanism?
aleksley [76]
D. Exercise promotes self-control
7 0
3 years ago
Read 2 more answers
Other questions:
  • Ice caps at the north and south poles are very reflective the ice reflects light and heat rather than absorbing it. If global wa
    15·1 answer
  • When does constructive interference occur?
    6·1 answer
  • 1
    6·1 answer
  • Please help me with this science question
    14·1 answer
  • The terms sanity and insanity:
    10·2 answers
  • Which of the following examples best describe using an inclined plane
    6·1 answer
  • A 3-cm high object is in front of a thin lens. The object distance is 4 cm and the image distance is –8 cm. (a) What is the foca
    7·1 answer
  • A 110 kg ice hockey player skates at 3.0 m/s toward a railing at the edge of the ice and then stops himself by grasping the rail
    6·1 answer
  • If you know how much radioactive material the organism had to begin with, explain how you could use half-life to determine its a
    14·1 answer
  • A6 kg bag of rice is on the top shelf at a grocery store.
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!