A 48-N object floats in a pool. If 75% of the volume of the object is immersed in the water, which statement is true about the buoyant force FB on the object?

Question

A. FB=48N
B. FB=36N
C. FB=64N
D. FB=12N
E. This is not possible to answer with the information given.

Answer 1

Do/Dw = 0.75.
Do/1 = 0.75, Do = 0.75g/cm^3 = Density of the object.

M*g = 48 N. M = 48/g = 48/9.8 = 4.90 kg. = 4900g = Wt. of object.

Vo = 4900g/(0.75g/cm^3) = 6533.3 cm^3 = Vol. of object.

0.75 * 6533.3 = 4900 cm^3 immersed = Vol. of water displaced.

4900cm^3 * 1g/cm^3 = 4900g = 4.9kg of water displaced.

Fb = M*g = 4.9 * 9.8 = 48 N.