A traffic accident causes a chemical lawn service tank trailer to spill 2 kg of a pesticide into a small river. The river velocity is 0.3 m/sec, the river has a uniform cross-sectional area of 2.7 m², and D_L is 300 m²/min.

a) For a point 1.3 km downstream, estimate the maximum concentration of pesticide that would be found after the spill.

b) At the same time corresponding to part (a), estimate the pesticide concentration at a distance of 1.0 km downstream from the spill.

c) Sketch a plot of the concentration vs. distance at the time corresponding parts (a) and (b).