Question

1. The rain spout is replaced with a tightly-fitting 2 inch diameter tube that extends downward 10 feet until it reaches the ground where it is capped. A hole with an unknown radius is going to be drilled 2 inches above the bottom of the tube so that pressurized water will create a jet out the side of the tube that will be used to drive a turbine. During a rainstorm, the outside barometric pressure drops to 100,900 Pa.
   1. If we assume that 2.25 L/min of rain enters the gutter and thus our pipe, what is the velocity of water when it enters the top of the pipe in m/s?
   2. If all the water that comes in the top flows out the bottom hole, what is the velocity of water when it exits the hole assuming that the entire tube is filled with water?
   3. Assuming that the bottom hole is small enough to be considered a flat surface, how big should the diameter of the bottom hole be to both maximize the velocity of the jet of water where it exits and also ensure that no water overflows over the top of the tube?

Answer 1