When you urinate, you increase pressure in your bladder to produce the flow. For an elephant, gravity does the work. An elephant urinates at a remarkable rate of 0. 0060 m3 (a bit over a gallon and a half) per second. Assume that the urine exits 1. 0 m below the bladder and passes through the urethra, which we can model as a tube of diameter 8. 0 cm and length 1. 2 m. Assume that urine has the same density as water, and that viscosity can be ignored for this flow.