Let A = i+j+k be a vector and B = 3 be any scalar,
Multiplying A and B,
AB = (i+j+k)3 = 3i+3j+3k
Which is a new vector whose direction is same as the old but it's 3 times greater in length than the old vector(i+j+k).
Now, dividing A and B,
A/B = (i+j+k)/3 =

Which is again a new vector whose direction is same as the old but now it's 1/3 times small in length than the old vector.
Direction is same because we multiplied by positive scalar. If we multiply A by suppose -1, -4, -1000000 or any negative number, it's direction will reverse.
Thus, if we multiply a vector with scalar, it's length increases. If we divide, it shrinks.
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:
Apparent depth (Da) = 60.15 cm (Approx)
Explanation:
Given:
Distance from fish (D) = 80 cm
Find:
Apparent depth (Da)
Computation:
We know that,
Refractive index of water (n2) = 1.33
So,
Apparent depth (Da) = D(n1/n2)
Apparent depth (Da) = 80 (1/1.33)
Apparent depth (Da) = 60.15 cm (Approx)