[填空题]
A fire truck is pumpii:ry )np7hhz1eb (zz)ng water at a ratv9jxp n2q ,40 tjg-inue of r=$\frac{2 t^{2}}{35}$ where r is in litres per second and is the time measured in seconds.
The graph of r is shown below.
1. Write down an integral that represents the area of the shaded region.
$A=\int_{x}^{y} \frac{a t^{2}}{b} \mathrm{~d} t$;a= ,b= ; x= ,y= .
2. 1. Find the area of the shaded region, rounding your answer to the nearest whole number.
2. Interpret the meaning of the shaded area in the context of this question.
3. Calculate the number of seconds it takes for the fire truck to pump $1000 \mathrm{~L}$ of water.
s≈ s (one decimal plaeaces)
