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
suter [353]
3 years ago
11

In a downtown office building, you notice each of the four sections of a rotating door has a mass of 75 kg. What is the width, i

n meters, of each section of the door if a force of 56 N applied to the outer edge of a section produces an angular acceleration of 0.420 rad/s2?
Physics
1 answer:
DENIUS [597]3 years ago
8 0

Answer:

each door has a width of 2.666 meters

Explanation:

from Newton's second law applied to rotational motion:

ζ = I α

where ζ= torque , I = moment of inertia , α = angular acceleration

the moment of inertia for a flat plate around its central axis is

I = 1/12 m a² , where m= mass, a= total width = 2L

therefore the moment of inercia for a flat plate with length 2L ( 2 doors, one in each side of the central axis) is

I1 = 1/12 m (2L)² = 1/3 m L²

if we have 4 doors , that is 2 flat plates with length of 2L perpendicular to each other:

I = Ix + Iy = 2*I1 = 2/3 m L²

thus

ζ = I α

4* F * L = 2/3 * (4*m) L² * α

L = 3/2* F/ ( m*α) = 3/2* 56 N / ( 75 Kg * 0.420 rad/seg²) = 2.666 m

You might be interested in
Note: the 2 in the answers are exponents
stiks02 [169]

Final speed after collision with the wall

v_f = -0.4 m/s

before collision the speed of ball initially

v_i = 0.6 m/s

time taken for the collision

\Delta t = 0.2 s

now as per the formula of acceleration we know that

a = \frac{v_f - v_i}{\Delta t}

now plug in all values in it

a = \frac{-0.4 - 0.6}{0.2}

a = -5.0 m/s^2

so acceleration is - 5 m/s/s for above situation

4 0
3 years ago
What term best describes the geologic event taking place in the above illustration?
grigory [225]

u lying you made me get it wrong, for ya'll out there who want the real answer is sea floor spreading

8 0
3 years ago
Read 2 more answers
What are the benefits of the cool-down period following exercise?
kvv77 [185]

The benefits of the cool down period are quite important, it allows your body to slow your heart rate at a nice healthy safe pace, if you stop right away it can cause breathing, heart, and muscle problems.


5 0
3 years ago
The friction force between a bag and the floor is 4 N. what is the net force acting on the bag? What is the acceleration of the
tester [92]
Well, if the bag is moving across the floor at a constant velocity. Then I would assume that the Fnet force is equal to 0, and thus the value of acceleration would also be equal to 0.
6 0
2 years ago
An Alaskan rescue plane traveling 41 m/s drops a package of emergency rations from a height of 192 m to a stranded party of expl
svet-max [94.6K]

Answer:

a)The package strikes 256.2 m in the ground relative to the point directly below where it was released

b) The horizontal component will not change it remains same as 41 m/s

c) Vertical component of velocity = 61.41 m/s

Explanation:

a) Consider the vertical motion of plane,

         We have equation of motion, s = ut + 0.5 at²

         Initial velocity, u = 0 m/s

         Displacement, s = 192 m

         Acceleration, a = 9.81 m/s²

         Substituting

                      s = ut + 0.5 at²

                      192 = 0 x t + 0.5 x 9.81 x t²

                         t = 6.26 seconds

         Now we need to find horizontal distance traveled in 6.26 seconds by the package.

         We have equation of motion, s = ut + 0.5 at²

         Initial velocity, u = 41 m/s

        Time, t = 6.26 s

         Acceleration, a = 0 m/s²

         Substituting

                      s = ut + 0.5 at²

                      s = 41 x 6.26 + 0.5 x 0 x 6.26²

                         s = 256.52 m

     The package strikes 256.2 m in the ground relative to the point directly below where it was released

b) The horizontal component will not change it remains same as 41 m/s

c) We have equation of motion, v = u+ at

          Initial velocity, u = 0 m/s

         Time, t = 6.26 s

         Acceleration, a = 9.81 m/s²  

         Substituting

                      v = u+ at

                       v = 0 + 9.81 x 6.26 = 61.41 m/s

   Vertical component of velocity = 61.41 m/s      

4 0
3 years ago
Other questions:
  • A student went to a hill station early in the morning, he could hear the echo of his clap after 0.1 second. When he went to the
    10·1 answer
  • the relationship between period and frequency is represented by the following equation: frequency = 1/period or period = 1/frequ
    12·2 answers
  • Why machines are never 100 percent efficient
    13·2 answers
  • Which of the following represents a system that is completely open?
    14·2 answers
  • What happens to the wavelength as the frequency of a whale noise changes from 200hz to 300hz
    14·1 answer
  • How much potential energy does a 20-kg barrel have when it is in the truck whose floor is 5.0 m above the ground? P.E. = J
    7·1 answer
  • A Dodge Stealth is driving at 70 mph on a highway. It passes a BMW going the same direction. The BMW is moving 7 mph backward re
    6·1 answer
  • NEED HELP THIS IS DUE IN 30 MINUTES
    10·1 answer
  • Calculate the parallel component of the weight of the object on the inclined plane below.
    7·1 answer
  • A hockey puck slides across the ice and eventually comes to a stop. Why did the puck stop?
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!