Q. The extension in a string obeying Hooke’s law is$x$. The speed of transverse waves in the stretched is$v$ . If the extension in the string is increased to 1.5 $x$, the speed of transverse waves in it will be
A) 1.22 v
B) 0.61 v
C) 1.5 v
D) 0.75 v
Explanation
(a) As$x \propto F$, therefore, when $x$ becomes $1.5$ times, $F\ $ becomes $1.5$ times.
As $v = \sqrt{\frac{T}{m}} = \sqrt{\frac{F}{m}},$therefore.
$v^{'} \propto \sqrt{1.5}v = 1.22v$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.