QUESTION Standing waves As shown in Figure 2, a standing wave is mains fixed in
ID: 1501598 • Letter: Q
Question
QUESTION
Standing waves As shown in Figure 2, a standing wave is mains fixed in position over time. Figure 2:Standing waves on a string. Standing waves can be produced by superposing two identical waves (having the same ampli- tude, speed, and wavelength) moving in opposite directions. In the lab, this is accomplished by fixing an end of string from which the incoming wave can almost perfectly reflect and superpose itself. The mathematical expression of a standing wave can be derived by adding together two counter-propagating waves y+ and y- (as shown in Section 3.1), as a wave whose shape re- /2 yswlx, t) = y+(x, t) + y.(x, t) = 2A cos(2nft) sinax)Explanation / Answer
if node is decreased by number 1.
then wavelength will increase.
so to keep wavelength same, we have to decrease the string length,
lambda = v / frequency
to decrease lambda, we have to increase frequency.
to decrease lambda , we have to decrease v.
and v = sqrt( T / linear density)
so we have to decrease the tension or increase linear density,
i. - increase
ii - decrease
iii - increase
iv - decreaese