# The equation of a wave pulse is given as y= 0.8/((4x+5t)+4) the amplitude and velocity…

Q:The equation of a wave pulse is given as $\displaystyle y = \frac{0.8}{(4x+5t)+4}$ the amplitude and velocity of the pulse are

(a)0.2 units, 1.25 units along –ve x-axis

(b)0.2 units, 1.25 units along +ve x-axis

(c)0.4 units, 1.25 units along –ve x-axis

(d)0.4 units, 1.25 units along +ve x-axis

Ans: (a)

Sol: $\displaystyle y_{max} = \frac{0.8}{4} = 0.2 m$

$\displaystyle 4 x + 5t = constant$

Differentiating w.r.t time

$\displaystyle 4 \frac{dx}{dt} + 5 = 0$

$\displaystyle \frac{dx}{dt} = – \frac{5}{4} = – 1.25 m/s$