`y(x, t) =(0.8)/([(4x + 5t)^(2) +5])` represents a moving pulse where `x` and `y` are in metre and `t` in second. Then,choose the correct alternative(s):
(a) pules is moving in positive x- direction
(b) in `2 s` it will travel a distance of `2.5 m`
(c) its maximum displacement is `0.16 m`
(d) it is a sysmmetric pulse

Options

A. pulse is moving in + x-direction
B. in `2 s` it will travel a distance of `2.5 m`
C. its maximum displacement is `0.16 m`
D. it is a symmetric pulse

Answer

B, C, D

Explanation

Given
`y = (0.8)/((4x + 5t)^(2)+5) =(0.8)/(16[x +(5)/(4)t]^(2)+5)`….(i)
We know that equation of moving pulse is
`y = f(x + vt)`…(ii)
On comparing Eqs. (i) and (ii), we get
`v = (5)/(4) m//s = (2.5)/(2) m//s`
Wave will travel a distance of `2.5 m` in `2 s`.