The figure shows the position – time (x – t) graph of one – dimensional motion of a body of mass 0.4 kg. The magnitude of each impulse is:

Options

A. 0.4 Ns
B. 0.8 Ns
C. 1.6 Ns
D. 0.2 Ns

Answer

B

Explanation

Here, mass of the body, m = 0.4 kg
Since position – time (x – t) graph is a straight line, so motion is uniform. Because of impulse direction of velocity change as it can be seen from the slopes of the graph.
From graph,
Initial velocity , `u = ((2 - 0))/((2 - 0)) = 1 ms^(-1) " Final velocity" , v = ((0 - 2))/((4 - 2)) = -1 m s^(-1)`
Initial momentum, `" " P_(i) = m u = 0.4 xx 1 = 0.4 Ns`
Final momentum, `P_f = mv = 0.4 (-1) = -0.8 Ns`
|Impulse | = 0.8 Ns.