Almost impossible to quantify. Depends on your metabolism and activity. I assume you intend to consume nothing but water for 3 weeks. I would do a little more research into the potential risks to your health before embarking on this mission. You risk malnourishment, changes in mental state, hypoglycaemias, and kidney damage.
121?! 5'6?! why do you need to lose weight anyways!!! probably quite a bit though..
That is 18,041.403 pounds
180/62.5 = 2.88 cubic feet
200 cubic feet of water weighs about 12,462.5 pounds or 6.23 tons.
Approximately 1,620.2 pounds.
If one liter of water weighs one kilogram then 27 cubic feet will have a weight of 1,685.55 pounds.
Approximately 1,419.34 pounds @8.34 pounds per US gallon.
you ar ea couple of pounds hevy but you can lose the weight fast.
Approximately 102 pounds for 1.63 cubic feet of water (12.2 US gallons).
The weight of 2.25 cubic feet of water is approx 4495 pounds-force (lbf).
Approximately 1,775.9 pounds.
Nothing. A weight is a force whereas a pound is a measure of mass. For example, a mass of 27 pounds would weight nothing in outer space (at the Lagrange points to be more precise), but would have a weight of millions of pound-weight near a black hole.
One cubic foot of water weighs about 62.4 pounds.