Answer
$(a) \space 21.6\space kNs$
$(b)\space 10.8\space m/s$
Work Step by Step
(a) According to the graph, the impulse is the area under the curve with $\vec F$ the average force.
$Impulse = F(\Delta t)$
According to the graph, we can assume that the, $F\approx100\times 0.27\space kN$
So we can write,
$Impulse\approx100\times 0.27\times10^{3}N\times800\times10^{-3}$
$Impulse\approx 21.6\space kNs-(1)$
(b) We know that the $\vec F=\frac{\Delta \vec p}{\Delta t}$
$\rightarrow \vec F(\Delta t)=\Delta \vec P$
$(1)=\gt$
$21.6kNs=\Delta m\vec V$
$21.6\times10^{3}Ns=2000\space kg(0-V)$
$\frac{21.6}{2}\space m/s= -V$
$V=-10.8\space m/s$
Initial speed = 10.8 m/s
