The following question is from an old UK A-Level Applied Mathematics textbook. I have tried to solve this, but the answer I get is different from that given in the book. Could anyone please see what I'm doing wrong, or is the book answer wrong?

An engine is pumping water from a large tank and delivering it through a pipe of diameter 0.04 m at a rate of 100 litre s^{-1}. Find the work done by the engine in one second.

This is my answer:

100 litres = 0.1 m^{3}, so the length of pipelfilled in one second is given by

The work done in one second is therefore given by

The book gives the answer as 317 kJ. What am I doing wrong?

Many thanks