To be a successful water polo player, one needs to have his head, arms, and part of the upper torso out of the water. Since floating alone won't work, players tread water. How much force is the swimmer exerting to keep his head, part of his torso, and his arms above the surface of the water? Use a free-body diagram and a force balance to solve this problem. The buoyant force acts in the direction opposite to gravity and is known to be equal to the weight of the fluid displaced by the object. Use Table to estimate the volume of the player that is in the water.
Approximate Displaced Volumes of Body Parts in Water
|
Body Part
|
Volume (in3)
|
|
Head
|
400
|
|
Torso
|
2000
|
|
Arm
|
350
|
|
Leg
|
700
|