Reconstruct quantities from their rates
Use the rate model and the boundary value to reconstruct the quantity
A collection vessel has capacity 500 L
Time t is measured in min. The model is valid only for 0 ≤ t ≤ 5. Q is the volume in litres, and its signed net rate is in L/min
\[Q'(t)=t+2\]
\[Q(0)=40\]
Find the volume at 4 min