How can i calculate the speed of an object in water

[DouglasEdward]

I would like to know how fast an object will move through sea water.
Do you know if an accurate figure can be calculated? if so how?
I would like to know how fast 100 tonnes of steel -(streamlined )would fall through sea water.
I would also like to how how to calculate the figure for any object.

 

[Sakha]

For a rough approximation you can just calculate gravity vs. buoyancy forces to determine the acceleration.

For a more accurate calculation you will need to take into account drag forces.

 

[QuantumPion]

These two wiki articles should provide you with what you need:

http://en.wikipedia.org/wiki/Terminal_velocity

http://en.wikipedia.org/wiki/Drag_coefficient

 

[DouglasEdward]

thanks for your replies,


where
Vt = terminal velocity,
m = mass of the falling object,
g = acceleration due to gravity,
Cd = drag coefficient,
ρ = density of the fluid through which the object is falling, and
A = projected area of the object.

i just want to chack i understnad the equation...

( 2xmass x accelaration gravity) divided by (density x area x drag coefficient)
= X square root of x = Vt

how accurate is this euquation considered to be; what is still missing.?

I put some very dense materials in with very low drag coefficients and i got figure up to 65 metre per second which seems a little fast

i got other things in and think that the figure is more realistic by making the drag coefficient 1 rather than 0.09.

 

[PJC01]

To calculate the speed of an object in water, you will need to use the equation for velocity, which is distance divided by time. In order to accurately calculate the speed of an object in water, you will need to know the distance the object travels and the time it takes to travel that distance.

The speed of an object in water is affected by several factors such as the density of the water, the shape and size of the object, and any external forces acting on the object. To accurately calculate the speed, you will need to take into account these factors and use the appropriate equations.

For a streamlined object like 100 tonnes of steel, the speed can be calculated using the equation for drag force, which is equal to the product of the drag coefficient, the density of the water, the velocity of the object squared, and the area of the object. By rearranging this equation, you can solve for the velocity of the object.

However, it is important to note that the actual speed of the object may vary due to other factors such as turbulence and water currents. Therefore, the calculated speed may not be completely accurate, but it can provide a good estimate.

To calculate the speed of any object in water, you will need to gather the necessary information such as the object's mass, dimensions, and any external forces acting on it. Then, you can use the appropriate equations, such as the ones for velocity and drag force, to calculate the speed.

In conclusion, while an accurate figure for the speed of an object in water may be challenging to calculate due to various factors, it is possible to estimate it using scientific equations and considering all relevant variables.