Homework Help: physics

Posted by Anonymous on Tuesday, May 1, 2012 at 10:35am.

A wooden cube with a specific gravity of 0.90 and side length 0.120 m is placed into a
bucket of water and floats upright with its sides in a horizontal or vertical orientation.
What is the mass of the cube, what is the buoyancy force acting on the cube and how
much of the cube projects above the surface?

physics - Elena, Tuesday, May 1, 2012 at 4:09pm
Let the length above the surface of the water is «x”,
a =0.120 m,
ρ1/ρ2 = 0.9. Since the density of water is ρ2 = 1000 kg/m³,
the density of wood is ρ1 = 900 kg/m³.
m•g = F(buoyancy force),
ρ1•V•g = ρ2•V1 •g
ρ1•a³•g = ρ2•a²•(a-x)•g,
ρ1/ ρ2 = (a-x)/a =0.9.
x = a – 0.9•a = 0.1•a =0.012 m.
The mass of the cube is
m = ρ1•a³ = 900•(0.12)³=1.56 kg.
The buoyancy force is
F = ρ2•a²•(a-x)•g = 1000•(0.12)² •(0.12 -0.012) •9.8 = 15.24 N.

Answer this Question

Related Questions

Math - A wooden block that is a rectangular prism is 12 inches long. Melinda ...
Math - A wooden block that is a rectangular prism is 12 inches long. Melinda ...
11th grade Physics - An open pipe 0.40m in length is placed vertically in a ...
algebra - the cube root of the volume of a cube gives the length of one side of ...
Algebra 1 - The cube root of the volume of a cube gives the length of one side ...
7th grade - Given a cube of density 8900kg/m3 and length side 10cm A-what is the...
physics - A cylindrical 7.25 kg pulley with a radius of 0.864 m is used to lower...
Calculus - An ice cube is melting such that the side of the cube is decreasing ...
Geometry - The ratio of the volume of cube A to the volume of cube B is 64 to 27...
Physics - A hydrometer is an instrument for measuring the specific gravity of a ...

For Further Reading

First Name:
School Subject:
Answer: