A cylinder inside a rectangular water tank

Core stretch

A solid cylinder of radius \(2r\) cm and height \(h\) cm stands inside a tank of dimensions \(6r\) cm by \(4r\) cm by \(h\) cm. Using \(\pi=3.14\), its volume is \(2512\text{ cm}^3\).

1. Express \(h\) in terms of \(r\).[2]
2. The tank is filled around the cylinder; find water volume in litres.[2]
3. After removing the cylinder, express the new water depth in terms of \(r\).[2]