Please explain, not just the answers. The amplitudes and phase differences for f
ID: 1523719 • Letter: P
Question
Please explain, not just the answers.
The amplitudes and phase differences for four pairs of waves of equal wavelengths are (a) 2 mm, 6 mm, and n rad; (b) 3 mm, 5 mm, and n rad; (c) 7 mm, 9 mm, and n rad; (d) 2 mm, 2 mm, and 0 rad. Each pair travels in the same direction along the same string. Without written calculation, rank the four pairs according to the amplitude of their resultant wave, greatest first. If multiple points rank equally, use the same rank for each, then exclude the intermediate ranking (i.e. if objects A, B, and C must be ranked, and A and B must both be ranked first, the ranking would be A:1, B:1, C:3). If all points rank equally, rank each as '1'. a b c d Greatest Second greatest Third greatest Fourth greatestExplanation / Answer
when phase difference is pi radians, they will add destructively. So resultant amplitude will be difference of both individuals.
when phase difference is 0 radians, they will add constructively. So resultant amplitude will be sum of both individuals.
for a : amplitude = |6-2|=4 mm
for b : amplitude = |5-3|=2 mm
for c : amplitude = |9-7|=2 mm
for d : amplitude = |2+2|=4 mm
Answer:
A:1
B:3
C:3
D:1