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
faltersainse [42]
3 years ago
12

A 30-cm-diameter, 1.2 kg solid turntable rotates on a 1.2-cm-diameter, 450 g shaft at a constant 33 rpm. When you hit the stop s

witch, a brake pad presses against the shaft and brings the turntable to a halt in 15 seconds. How much friction force does the brake pad apply to the shaft?
Physics
1 answer:
skelet666 [1.2K]3 years ago
6 0

Answer:

frictional force = 0.52 N

Explanation:

diameter of turn table (D1) = 30 cm = 0.3 m

mass of turn table (M1) = 1.2 kg

diameter of shaft (D2) = 1.2 cm = 0.012 m

mass of shaft (M2) = 450 g = 0.45 kg

time (t) = 15 seconds

acceleration due to gravity (g) = 9.8 m/s^{2}

radius of turn table (R1) = 0.3 / 2 = 0.15 m

radius of shaft (R2) = 0.012 / 2 = 0.006 m

total moment of inertia (I) = moment of inertia of turn table + moment of inertia of shaft

I = 0.5(M1)(R1)^{2} + O.5 (M2)(R2)^{2}

I =  0.5(1.2)(0.15)^{2} + O.5 (0.45)(0.006)^{2}

I = 0.0135 + 0.0000081 = 0.0135081

ω₁ = 33 rpm = 33 x \frac{2π}{60} = 3.5 rad/s

α = -ω₁/t = -3.5 / 15 = -0.23 rad/s^{2}

torque = I x α

torque = 0.0135081 x (-0.23) = - 0.00311 N.m

torque = frictional force x R2

- 0.00311 = frictional force x 0.006

frictional force = 0.52 N

You might be interested in
The magnetic field inside a superconducting solenoid is 4.00 T. The solenoid has an inner diameter of 6.20 cm and a length of 26
Delvig [45]

Answer:

(a) The magnetic energy density in the field is 6.366 J/m³

(b) The energy stored in the magnetic field within the solenoid is 5 kJ

Explanation:

magnitude of magnetic field inside solenoid, B = 4 T

inner diameter of solenoid, d = 6.2 cm

inner radius of the solenoid, r = 3.1 cm = 0.031 m

length of solenoid, L = 26 cm = 0.26 m

(a) The magnetic energy density in the field is given by;

u _B = \frac{B^2}{2\mu_o} \\\\u _B = \frac{(4)^2}{2(4\pi*10^{-7})}\\\\u_B = 6.366*10^6 \ J/m^3

(b) The energy stored in the magnetic field within the solenoid

U_B = u_B V\\\\U_B = u_B AL

U_B = u_B(A)(L)\\\\U_B = 6.366*10^6(\pi * 0.031^2)(0.26) \\\\U_B = 4997.69 J\\\\U_B = 5 \ KJ\\

6 0
3 years ago
Which of the following statements about galaxies is true? A. Galaxies typically contain millions of stars. B. Galaxies actually
Sloan [31]

the answer is D i took the quiz so it is definitely D  

6 0
3 years ago
Read 2 more answers
Intermolecular forces hold
blagie [28]
I believe Intermolecular forces hold, <span>molecules, ions, and atoms? But I would see if that doesn't sound familiar check it with a site or something?</span>
3 0
2 years ago
You drop a ball from a height of 32 meters how much time passes before the ball hits the ground
tankabanditka [31]

Answer:

31 seconds

Explanation:

ajsfhlAS

5 0
3 years ago
What is current electricity?​
olganol [36]
Electric current is the movement of electrons through a wire. Electric current is measured in amperes (amps) and refers to the number of charges that move through the wire per second.
4 0
2 years ago
Other questions:
  • A ball having a mass of 0.20 kilograms is placed at a height of 3.25 meters. If it is dropped from this height, what will be the
    10·2 answers
  • Can been seen but not projected?
    6·1 answer
  • When atoms bond together, they make:
    11·2 answers
  • ILL RATE YOU A 5, THANK YOU, AND MARK YOU AS BRAINLIEST! HURRY!
    13·2 answers
  • Can you correctly identify facts about these two historical models of the solar system?
    9·1 answer
  • A (Blank) supplies energy to move electricity through a circuit
    7·1 answer
  • Find initial velocity and time in air​
    5·1 answer
  • 10. At point A, a runner is jogging 5 m/s. Forty seconds later, at point B
    13·1 answer
  • An electric field has a positive test charge of 5.00 C placed in it. The force on the test charge is
    10·1 answer
  • Would you expect to weigh more on an ocean beach or on top of a mountain? Explain.
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!