If the aim is to let a 700 kg pump float on the surface of water, how many cylinders ( 50cm*90cm ) containing (( 2/3 from total volume / cylinder )) fresh water should we have ?
The net buoyancy force on a 2/3 full cylinder of water will depend upon the weight of the empty cylinder, which is not specified.
the mass of empty cylinder is 10 kg and the weight is 98 N
How I can let the 700 Kg floats on the surface of water by using cylinders with r=50cm , h=90cm & 2/3 full volume fresh water ? how many cylinders we need ? Is 2/3 full volume better than 1/2 volume ?
In your 50*90 cylinder dimensions, which is the diameter and which is the length? It matters when computing the volume.
The emptier the cylinder, the fewer you need for flotation. Is that also your drinking water supply?
diameter = 50 cm and length = 90 cm. and the purpose to let the pump float on the surface , while the cylinders under water totally.( top surface of cylinder touching the surface of water )
To determine the number of cylinders required to let a 700 kg pump float on the surface of water, we need to calculate the total volume of water needed to counterbalance the weight of the pump.
1. Start by finding the weight of the water needed to offset the 700 kg pump. Since the density of water is 1000 kg/m³, the weight of the water required is equal to the weight of the pump. So, the weight of the water needed is also 700 kg.
2. Calculate the volume of water needed by dividing the weight of the water by the density of water:
Volume = Weight / Density = 700 kg / 1000 kg/m³ = 0.7 m³
3. Now, let's calculate the volume of each cylinder. The formula for the volume of a cylinder is:
Volume of Cylinder = π * (radius)² * height
Given that the dimensions of the cylinder are 50 cm * 90 cm, we need to convert them to meters:
Radius = (50 cm) / 100 = 0.5 m
Height = (90 cm) / 100 = 0.9 m
Plug these values into the formula to find the volume of each cylinder:
Volume of Cylinder = π * (0.5 m)² * 0.9 m = 0.70685 m³
4. Finally, divide the total volume of water needed by the volume of each cylinder to find the number of cylinders required:
Number of Cylinders = Total Volume / Volume of Cylinder = 0.7 m³ / 0.70685 m³ ≈ 0.989 cylinders
So, in order to let a 700 kg pump float on the surface of water, you would need approximately 0.989 cylinders. Since you cannot have fractional cylinders, you would need at least 1 cylinder.