JEE MainPhysicsOscillations
A particle executes simple harmonic motion. Which of the following describes the graph showing the variation of its potential energy ( PE ) with the magnitude of its velocity ( v ) as it moves from the extreme position to the mean position?
Options
- AA downward-opening parabola with its vertex on the positive PE axis
- BAn upward-opening parabola passing through the origin
- CA straight line with a negative slope
- DA straight line passing through the origin with a positive slope
Correct answer
A. A downward-opening parabola with its vertex on the positive PE axis
Step-by-step solution
The potential energy ( PE ) of a particle in SHM is given by PE = 1 2 m ^2x^2 . The velocity v of the particle is related to its displacement x by the equation v^2 = ^2(A^2 - x^2) , where A is the amplitude. Rearranging this for x^2 , we get x^2 = A^2 - v^2 ^2 . Substituting this into the potential energy equation: PE = 1 2 m ^2 (A^2 - v^2 ^2 ) = 1 2 m ^2A^2 - 1 2 mv^2 This equation is of the form y = -cx^2 + k (where c and k are positive constants). This represents a downward-opening parabola with its maximum valu