Question
Force – time curve for a body of mass 7.59 kg is shown in the figure. What is the velocity of the body at the end of 10s? Assume the body starts from rest.
Solution
Area under Force–time graph is equal to the impulse or change in the momentum of the body.
Now, Area under F–t graph,
From, t = 0 to t = 10s = Area of trapezium 1+ Area of trapezium 2 + Area of rectangle 3
= 34 + 28.5 + 21 = 83.5
∴ Change in momentum of body = 83.5 Ns
i.e. m(v - 0) = 83.5 
7.59 x v = 83.5 
v = 11 m/s, is the velocity of the body.
