Question

Fig. shows the position-time graph of a particle of mass 0.04 kg. Suggest a suitable physical context for this motion. What is the time between two consecutive impulses received by the particles? What is the magnitude of each impulse?

Answer 1

This graph can be of a ball rebounding between two walls situated at position 0 cm and 2 cm. The ball is rebounding from one wall to another, time and again every 2 sec. with uniform velocity.

Here, velocity = {displacement}/{time}

= {2}/{100 x 2} = 0.01 ms^-1

Initial momentum = mu = 0.04 x 0.01 = 4 x 10^-4 kg ms^-1

Final momentum = mv = 0.04 x (-0.01)

= -4 x 10^-4 kg ms^-1

Magnitude of impulse = change in momentum

= (4 x 10^-4) - (-4 x 10^-4)

= 8 x 10^-4 kg ms^-1

Time between two consecutive impulses is 2 s, i.e., the ball receives an impulse every two seconds.