From Newton's second law of motion,
F = m*a
= m * (change in velocity)/time [As a = (change in velocity)/time]
From the question, we know
F = 400 N, time = 5 s
Therefore,
400 = 1000 * (change in velocity)/5
i.e. change in velocity = 2 m/s
Momentum = m * velocity
Therefore,
Change in momentum = (change in mass) * (change in velocity)
= 1 * (change in velocity) [As m remains the same]
= 1 * 2
= 2 kgm/s
