OnlineCBT
Physics · WORK, ENERGY AND POWER
हिन्दीConsider the following statements for a mass-spring system obeying Hooke's law (\( F = -kx \)) undergoing oscillations between \( -x_m \) and \( +x_m \): (A) The potential energy curve \( V(x) \) versus displacement \( x \) is a parabola opening upwards. (B) The kinetic energy curve \( K(x) \) versus displacement \( x \) is a parabola opening downwards. (C) The total mechanical energy \( E = K + V \) varies sinusoidally with displacement \( x \). (D) At turning points \( x = \pm x_m \), the kinetic energy is maximum and potential energy is zero. Which of the above statements are correct?
Correct answer · Option 3
(A) and (B) only
Explanation
\( V(x) = \frac{1}{2}kx^2 \) is an upward-opening parabola (A is true). \( K(x) = \frac{1}{2}k(x_m^2 - x^2) \) is a downward-opening parabola (B is true). \( E \) is constant (C is false). At turning points, \( K = 0 \) and \( V \) is maximum (D is false).
