ExamBro
ExamBro
MHT CET · Physics · Oscillations

The potential energy of 'a long spring when it is stretched by 3 cm is ' \(U\) '. If the spring is stretched by 9 cm , potential energy stored in it will be

  1. A \(3 \dot{U}\)
  2. B \(4 U\)
  3. C 5 U
  4. D \(9 U\)
Verified Solution

Answer & Solution

Correct Answer

(D) \(9 U\)

Step-by-step Solution

Detailed explanation

P.E. stored in spring is, \(\mathrm{U}=\frac{1}{2} \mathrm{kx}^2\)
\(\begin{array}{ll}
\therefore & \frac{U^{\prime}}{U}=\left(\frac{x_2}{x_1}\right)^2=\left(\frac{9}{3}\right)^2=(3)^2=9 \\
\therefore & U^{\prime}=9 U
\end{array}\)