question_answer 20)

Figure 3.90 gives the x-t plot of a particle executing le-dimensional simple harmonic motion. Give the signs of position, velocity and acceleration variables of the particle at t = 0.35, 1.25, -1.2s.    

Answer:

The acceleration of a particle executing S.H.M. is given by                                             where  (angular frequency) is a constant. At time t = 0.3 s As is obvious from the graph, x < 0 As slope of x-t graph is negative, so As so a > 0. At time t =1.2 s As is obvious from the graph, x > 0 As slope of  graph is positive, so As      so   At time t = - 1.2s As is obvious from the graph, x < 0 As slope of  graph is positive, so As  so a>0.