Figure shows the variation of force acting on a body with time. Assuming the body to start from rest, the variation of its momentum with time is best represented by which plot?

From 0 to 2 s: at any time t, F =10 t⇒ a=F/m=10t/m⇒ ∫0v dv=∫0t 10tmdt⇒v=5t2mMomentum: p=mv=5t2 At t=2s,p=5(2)2=20kgms−1,v=20/m From 2 to 4s:F=40−10t∫20/mv dv=∫2t 40−10tmdt⇒v=1m40t−40−5t2p=mv=40t−40−5t2