Suppose you adjust your garden hose nozzle for a hard stream of water. You point the nozzle vertically upward at a height of 1.5m above the ground. When you quickly move away from the vertical you hear the water striking the ground next to you for another 2.0s. What is the water speed as it leaves the nozzle?

How should I approach this problem? How do I know what equations I should be using for this type of problem?