Question

The potential energy of a particle with displacement X is U(X). The motion is simple harmonic, when (K is a positive constant)

• A. U = -
• B. U =
• C. U=K
• D. U=KX

Answer 1

The correct option is A

U = -

F = - kx $\Rightarrow$ dW = F dx = - kxdx

So ${\int }_0^{W}dW={\int }_0^x-kxdx\Rightarrow W=U=-\frac{1}{2}k{x}^2$