Question

For any S.H.M., amplitude is 6 cm. If instantaneous potential energy is half the total energy then distance of particle from its mean position is

• A. 3 cm
• B. 4.2 cm
• C. 5.8 cm
• D. 6 cm

Answer 1

Answer: (B)

4.2 cm

Answer 2

If at any instant displacement is y then it is given that

$U = \frac{1}{2} \times E$ ⇒ $\frac{1}{2}m\omega^{2}y^{2} = \frac{1}{2} \times \left( \frac{1}{2}m\omega^{2}a^{2} \right)$

⇒ $y = \frac{a}{\sqrt{2}} = \frac{6}{\sqrt{2}} = 4.2cm$