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
umka2103 [35]
3 years ago
11

Two speakers face each other, and they each emit a sound of wavelength . One speaker is 180 out of phase with respect to the oth

er. If we separate the speakers by a distance 1.5, how far from the left-most speaker should we place a microphone in order to pick up the loudest sound? Ignore reflections from nearby surfaces.
A. 1/2 lambda
B. 0 lambda
C. lambda
D. 3/4 lambda
E. 1/4 lambda
Physics
1 answer:
lutik1710 [3]3 years ago
8 0

Answer:

C. lambda

Explanation:

Loudest sound is heard where path difference of sound wave coming from two sources will be either zero or integral multiple of wavelength . Here waves are already out of phase by 180° so at t = 0 , there is a path difference of λ /2 where λ is wavelength . So taking into account this fact , for constructive interference , path difference needed is odd multiple of λ /2

Distance between the sources = 1.5 λ .

If we place the microphone at λ , path difference between the waves coming from two sources reaching microphone = λ - 0.5λ = 0.5λ . Hence at the point constructive interference will take place .

You might be interested in
You are helping your friend move a new refrigerator into his kitchen. You apply a horizontal force of 275 N in the positive x di
Volgvan

Answer:

f = 347.08 N

Explanation:

The frictional force exerted by the floor on the refrigerator is given as follows:

f = \mu R = \mu W

where,

f = frictional force = ?

μ = coefficient of static friction = 0.58

W = Weight of refrigerator = mg

m = mass of refrigerator = 61 kg

g = acceleration due to gravity = 9.81 m/s²

Therefore,

f = \mu mg\\f = (0.58)(61\ kg)(9.81\ m/s^2)\\

<u>f = 347.08 N</u>

8 0
3 years ago
Three ideal polarizing filters are stacked, with the polarizing axis of the second and third filters at 21 degrees and 61 degree
kvv77 [185]

Answer:

1

When second polarizer is removed the intensity after it passes through the stack is    

                    I_f_3 = 27.57 W/cm^2

2 When third  polarizer is removed the intensity after it passes through the stack is    

                I_f_2 = 102.24 W/cm^2

Explanation:

  From the question we are told that

       The angle of the second polarizing to the first is  \theta_2 = 21^o  

        The angle of the third  polarizing to the first is     \theta_3 = 61^o

        The unpolarized light after it pass through the polarizing stack   I_u = 60 W/cm^2

Let the initial intensity of the beam of light before polarization be I_p

Generally when the unpolarized light passes through the first polarizing filter the intensity of light that emerges is mathematically evaluated as

                     I_1 = \frac{I_p}{2}

Now according to Malus’ law the  intensity of light that would emerge from the second polarizing filter is mathematically represented as

                    I_2 = I_1 cos^2 \theta_1

                       = \frac{I_p}{2} cos ^2 \theta_1

The intensity of light that will emerge from the third filter is mathematically represented as

                  I_3 = I_2 cos^2(\theta_2 - \theta_1 )

                          I_3= \frac{I_p}{2}(cos^2 \theta_1)[cos^2(\theta_2 - \theta_1)]

making I_p the subject of the formula

                  I_p = \frac{2L_3}{(cos^2 \theta [cos^2 (\theta_2 - \theta_1)])}

    Note that I_u = I_3 as I_3 is the last emerging intensity of light after it has pass through the polarizing stack

         Substituting values

                      I_p = \frac{2 * 60 }{(cos^2(21) [cos^2 (61-21)])}

                      I_p = \frac{2 * 60 }{(cos^2(21) [cos^2 (40)])}

                           =234.622W/cm^2

When the second    is removed the third polarizer becomes the second and final polarizer so the intensity of light would be mathematically evaluated as

                      I_f_3 = \frac{I_p}{2} cos ^2 \theta_2

I_f_3 is the intensity of the light emerging from the stack

                     

substituting values

                     I_f_3 = \frac{234.622}{2} * cos^2(61)

                       I_f_3 = 27.57 W/cm^2

  When the third polarizer is removed  the  second polarizer becomes the

the final polarizer and the intensity of light emerging from the stack would be  

                  I_f_2 = \frac{I_p}{2} cos ^2 \theta_1

I_f_2 is the intensity of the light emerging from the stack

Substituting values

                  I_f_2 =  \frac{234.622}{2} cos^2 (21)

                     I_f_2 = 102.24 W/cm^2

   

7 0
3 years ago
A particle moves along a straight line and its position at time t is given by
Alisiya [41]

(A) Use interval notation to indicate the time interval or union of time intervals when the particle is moving forward and backward

the particle is speeding up

<span>if  a(t) >0, it means 12t-48>0, and t >4,  I = ]4, infinity[</span>

the particle is speeding down

<span>if  a(t) < 0, it means 12t-48>0, and t < 4,  I = ] -infinity, 4[</span>

 

when the particle is moving forward and backward

that is depending of the sign of v(t)

moving forward if v(t)> 0

<span>moving backward if v(t)<  0</span>

but v(t) = 6t² - 48 t +90, this quadratic equation has exactly two solutions, t =1, and t =3

<span>so  after taking care the sign of </span>6t² - 48 t +90,

 

<span>v(t)> o when  t is in I = ] –inf, 1[ U ]4, inf[,the particle is moving forward</span>

<span>v(t) < o when  t is in I = ]1, 4[,the particle is moving backward</span>

<span> </span>

3 0
3 years ago
Which of these is NOT a physical property?
m_a_m_a [10]
I believe the answer is chemical reactivity because: Characteristics such as melting point, boiling point, density, solubility, color, odor, etc. are physical properties.
8 0
2 years ago
a ball is thrown horizontally from a 20 m high building with a speed of 5.0 m/s. How far from the base of the building does the
kipiarov [429]
Given:
Dy= 20 m
Vi = 5.0 m/s horizontally
A=9.81 m/s^2

Find:
Horizontal displacement

Solution:
D=ViT+(1/2)AT^2
Dy=(1/2)AT^2
T^2=Dy/(1/2)A
T=sqrt(Dy/(1/2)A)
T=sqrt(20/4.905)
T=2.0s

Dx=ViT
Dx=(5.0)(2.0)
Dx=10. meters
7 0
3 years ago
Other questions:
  • Which region is located between 23.5° north and 23.5° south of the equator?
    15·1 answer
  • Which two of the following are the least dense materials shown?
    15·2 answers
  • Enter the expression 2cos2(θ)−1, where θ is the lowercase Greek letter theta.
    10·1 answer
  • In an atom, electrons ____.
    15·2 answers
  • Explain the difference between contact and non-contact forces. Give an example of each
    6·2 answers
  • 1- Kilogram is a unit of _____________ in ______________ system ?
    9·1 answer
  • Estimate the average power of a water wave when it hits the chest of an adult standing in the water at the seashore. Assume that
    12·1 answer
  • QUESTION 3
    12·1 answer
  • A dog is pulling on a leash while walking down
    9·1 answer
  • A different group is worried that the motion detector will not
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!