Answer:
a. 3/4λ
d. 1/4λ
Explanation:
When the wavelength of the sound waves is λ and the two waves are having same frequency the waves are said to be out of phase if their phase difference is in the multiples of
or 180°.
When the two waves are out of phase then their opposite maxima coincide at the same time resulting in the minimum amplitude of the resulting wave throughout.
- As we observe from the schematic that the a wave has sinusoidal pattern of variation and we get a maxima after each
of the distance.
- Here we have two speakers out of phase therefore on shifting one of the speakers by the odd multiples of
we have the maxima or the extreme amplitudes.
So, we must place the microphone at 3/4λ and 1/4λ to pickup the loudest sound.
Answer:
(a) Angle of incidence for violet is more than the angle of incidence for red
(b) 2.4°
Explanation:
refractive index for violet , v = 1.66
refractive index for red, nR = 1.61
wavelength for violet, λv = 400 nm
wavelength for red, λR = 700 nm
Angle of refraction, r = 30°
(a) Let iv be the angle of incidence for violet.
Use Snell,s law
nv = Sin iv / Sin r
1.66 = Sin iv / Sin 30
Sin iv = 0.83
iv = 56°
Use Snell's law for red
nR = Sin iR / Sin r
where, iR be the angle of incidence for red
1.61 = Sin iR / Sin 30
Sin iR = 0.805
iR = 53.6°
So, the angle of incidence for violet is more than red.
(b) iv - iR = 56° - 53.6° = 2.4°
Answer:
Explanation:
If I assume that the wind did not cause the plane to chage its velocity.
The plane will have a velocity of vp = (0*i + 100*j) km/h relative to ground
The cart has a velocity of vc = (0*i - 20*j) km/h relative to the plane
vc' = vc + vp
vc' = (0*i + 100*j) + (0*i - 20*j) = (0*i + 80*j) km/h relative to the ground.
If I assume that the wind move the plane:
The plane will have a velocity of vp = (-40*i + 100*j) km/h relative to ground
The cart has a velocity of vc = (0*i - 20*j) km/h relative to the plane
vc' = vc + vp
vc' = (-40*i + 100*j) + (0*i - 20*j) = (-40*i + 80*j) km/h relative to the ground.
In reality the wind would move the plane a little, not to the full speed of the wind, somewhere between these two values, but without more data it cannot be calculated.
Answer:
longitudinal wave
Explanation:
it is perpendicular to the direction of the wave
To solve this problem we will apply the concepts related to the kinematic equations of linear motion. From them we will consider speed as the distance traveled per unit of time. Said unit of time will be cleared to find the total time taken to travel the given distance. Later with the calculated average times and distances, we will obtain the average speed.
PART A)
The time taken to travel a distance of 250km with a speed of 95km/h is



Time taken for the lunch is

The time taken travel a distance of 250km with a speed of 55km/h



The total time taken is



The average speed is the ratio of total distance and total time


PART B)
As the displacement is zero the average velocity is zero.