Tamil Nadu Board of Secondary EducationHSC Science Class 11

# Consider the following function- (a) y = x² + 2 α tx(b) y = (x + vt)²which among the above function can be characterized as a wave? - Physics

Numerical

Consider the following function-

1. y = x² + 2 α tx
2. y = (x + vt)²

which among the above function can be characterized as a wave?

#### Solution

Formula:

For the function to be a wave function ("dy"//"dx")/("dy"//"dt") should be a constant.

For function (a):

y = x² + 2 α tx

$\frac{\text{dy}}{\text{dx}}$ = 2x + 2α t   ...(1)

$\frac{\text{dy}}{\text{dt}}$ = 0 + 2αx    ...(2)

((1))/((2)) => ("dy"//"dx")/("dy"//"dt") = (2x + 2alpha"t")/(2alpha"x")

For function (b):

y = (x + vt)2

$\frac{\text{dy}}{\text{dx}}$ = 2(x + vt)   ....(3)

$\frac{\text{dy}}{\text{dt}}$ = 2(x + vt)v    .....(4)

((3))/((4)) => ("dy"//"dx")/("dy"//"dt") = (2("x" + "vt"))/(2("x" + "vt")"v") = constant

Hence, function
(a) does not describe a wave.
(b) satisfies wave function.

Concept: Introduction to Waves
Is there an error in this question or solution?
Chapter 11: Waves - Evaluation [Page 279]

Share