help me.. volume loss?

Question

.It is a dark and stormy night. our secret agent, 008 is behind enemy lines at a fuel depot. she walks over to a cylindrical tank, w/c is 20 ft. tall and 8 feet in diameter. the tank is full. our agent opens a 2 inch diameter circular nozzle. she knows that the volume of the fuel leaving the tank is

volume lost(ft3)=velocityx(area of nozzle)xtime <----( i dont know if this is a the formula..? what do you think??)

and that,
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volume(ft/sec)=8.02x #8730;height of the fluid tank

our agent must radio in a report giving the approximate height of the fluid in the tank minute by minute until the tank is empty. she can first calculate the volume lost over one minute and assume taht the loss of fluid is constant. next she can then subtrat the volume from the tank and determine the new height of the fluid inside the tank at the end of the minute. then she can calculate the loss for the next minute. these calculations must be repeated over and over until the tank is dry.

Answer 1

Difficult problem and I don't understand all of it. I do agree with volume lost(ft3)=velocityx(area of nozzle)xtime. But how would you determine velocity? I suppose there is a formula for that but I don't know it.

I can't make sense of the line
volume(ft/sec)=8.02x #8730;height of the fluid tank. Don't know what that means.

This is not a good assumption: assume taht the loss of fluid is constant. The velocity will decrease as the height in the tank decreases until near the end it is a trickle relative to the flow at first. This is the main thing making it difficult.