How much does a one hundred and fifty pound person weigh in a swimming pool?

Question

my dad weighs 150 lbs, i can lift him quite easily in the pool , but not so easily on dry land.

Answer 1

As a lifeguard, when I went through training I was told that the 20 pound brick I was carrying simulated 150 pounds of person.

So about 20 pounds.

Answer 2

He still weighs 150lbs :P

The bouncy of of the water is what is helping to lift the weight. To determine how much force is required to lift him in the water compared to lifting him on dry land, you would also need to know the volume of the person to determine their density and compare that to water.

Ironically, since muscle is more dense than fat, the more fat on the persons body the less dense their body will be and thus they will seem to weigh less in water... even though they may actually weight far more.

Water weighs approximately 1 gram per cubic centimeter at room temperature. Since most people barely float or sink, and our bodies are 75% water, we are also about 1g/cm^3 density as well. Thus, he should still "weigh" near 150lbs.