Water pressure on base of cube

In summary, the conversation discusses the calculation of water pressure on the base of a floating cube of wood with a side length of 4cm in fresh water. The density of the wood is unknown and help is requested to determine the water pressure and wood density. The depth of the bottom of the cube is mentioned to be 3cm below the surface, and it is clarified that the water pressure is independent of the position along this horizontal line.
  • #1
Molly1235
77
4
"A cube of wood of side 4cm floats in fresh water with 1:4 showing above the surface.
Calculate a) the water pressure on the base of the cube and b) the density of the wood"

All I can work out is that the density of fresh water is 1000kgm^-3 and the area of the base is 1.6 x 10^-5 m.

Please can someone help?? I don't know where to start...
 
Physics news on Phys.org
  • #2
How deep (below surface) is the bottom of the cube?
 
  • #3
nasu said:
How deep (below surface) is the bottom of the cube?

3cm?
 
  • #4
Right!

Remember that the hydrostatic water pressure strictly depends on the vertical, that is, it doesn't matter whether you calculate the pressure directly BENEATH the cube, or anywhere else along the horizontal line lying 3 cm below the surface.
 
  • #5
OK, now calculate the pressure at this depth.
 

1. What is water pressure?

Water pressure is the force exerted by water on an object. It is caused by the weight of the water above the object and is measured in units of force per unit area, such as pounds per square inch (psi) or newtons per square meter (N/m²).

2. How does water pressure affect the base of a cube?

The water pressure on the base of a cube is equal to the weight of the water above it, divided by the area of the base. As the depth of the water increases, so does the pressure on the base of the cube.

3. Does the shape of the cube affect the water pressure on its base?

No, the shape of the cube does not affect the water pressure on its base as long as the base remains the same size. The water pressure is determined by the depth of the water and the area of the base, not the shape of the object.

4. What is the formula for calculating water pressure on the base of a cube?

The formula for calculating water pressure on the base of a cube is P = ρgh, where P is the pressure, ρ is the density of water, g is the acceleration due to gravity, and h is the depth of the water. This formula can also be written as P = ρgV/A, where V is the volume of water above the cube and A is the area of the base.

5. How does water pressure on the base of a cube change with depth?

Water pressure on the base of a cube increases with depth. This is because the weight of the water above the cube increases with depth, causing a greater force to be exerted on the base. This can also be seen in the formula for water pressure, where the depth of the water is a factor in the calculation.

Similar threads

  • Introductory Physics Homework Help
Replies
15
Views
1K
  • Introductory Physics Homework Help
Replies
1
Views
2K
  • Introductory Physics Homework Help
Replies
13
Views
2K
  • Introductory Physics Homework Help
Replies
9
Views
936
  • Introductory Physics Homework Help
Replies
15
Views
843
  • Introductory Physics Homework Help
Replies
3
Views
908
  • Introductory Physics Homework Help
Replies
2
Views
683
Replies
207
Views
3K
  • Introductory Physics Homework Help
Replies
5
Views
2K
  • Introductory Physics Homework Help
Replies
7
Views
2K
Back
Top