physics
posted by Anonymous .
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?

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•(ax)•g,
ρ1/ ρ2 = (ax)/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•(ax)•g = 1000•(0.12)² •(0.12 0.012) •9.8 = 15.24 N.
Respond to this Question
Similar Questions

Physics  Fluids
A cube of side length 11.0 cm and made of unknown material floats at the surface between water and oil. The oil has a density of 810 kg/m^3. a)If the cube floats so that it is 70% in the water and 30% in the oil, what is the mass of … 
Physics
A cube of oak with sides 15cm long floats upright in water with 10.5cm of its depth submerged. What is the density of the oak? 
11th grade Physics
An open pipe 0.40m in length is placed vertically in a cylindrical bucket having a bottom area of 0.10 m^2. Water is poured into the bucket until a sounding tuning fork of frequency 440 Hz, placed over the pipe, produces resonance. … 
Physics
A hydrometer is an instrument for measuring the specific gravity of a liquid. For example, producers of maple syrup use the hydrometer to find how much sugar is in the collected sap. Markings along a stem are calibrated to indicate … 
Physics
A fire helicopter carries a 555 kg empty water bucket at the end of a cable 20.9 m long. As the aircraft flies back from a fire at a constant speed of 38.4 m/s, the cable makes an angle of 38.3° with respect to the vertical. A) After … 
Physics
A wooden cube of side 5cm floats in water 200cm^2 of its depth below the water surface and ats sides are vertical calculate the density of the wood in g/cm^3.(1) Density of water in 1g(m^3). 
physics
Q.a cube of wood 20cm on each side,floats in water so that 30% is above the surface of the water,and 70% is below.what is the density of the wood(justify the answer) i.what mass of lead mass has to be placed on the top of the block … 
physics
Q.A cube of wood 20cm on each side,floats in water so that 30% is above the surface of the water,and 70% is below. i.what is the density of the wood(justify the answer) ii.what mass of lead mass has to be placed on the top of the block … 
physics, buoyance
A wood cube 0.20m on each side has a density of 730kg/m3 and floats levelly in water. Part A What is the distance from the top of the wood to the water surface? 
Physics
A wood cube 0.20m on each side has a density of 730kg/m3 and floats levelly in water. What mass has to be placed on top of the wood so that its top is just at the water level?