Originally posted by Syed F. Karim
Let's say that I rig up a truck to a giant helium balloon, but I load up the back of the truck with enough stones so that the truck has reached a state of neutral buoyancy--its just floating in mid-air, not rising not falling, just there. Now let's say I take away a one-pound rock from the truck's bed. Does the truck now have a positive lift of one pound? And will it now rise just like a small balloon with one pound of positive lift?
Originally posted by Syed F. Karim
Let's say that I rig up a truck to a giant helium balloon, but I load up the back of the truck with enough stones so that the truck has reached a state of neutral buoyancy--its just floating in mid-air, not rising not falling, just there. Now let's say I take away a one-pound rock from the truck's bed. Does the truck now have a positive lift of one pound? And will it now rise just like a small balloon with one pound of positive lift?
a=f/mOriginally posted by Syed F. Karim
If a small balloon with a positive lift of one pound has an ascent rate of 1000ft/min, would a 1000lb-truck with the same one-pound positive lift have an ascent rate of just 1ft/min? Is it an inverse relationship? How do you calculate the rate of ascent of massive bodies? (This is not a homework problem, I am an inventor.)
Buoyancy is the upward force exerted by a fluid on an object immersed in it. It is caused by the difference in pressure between the top and bottom of the object, with the pressure being higher at the bottom. This results in a net upward force, known as buoyant force, that counteracts the weight of the object and allows it to float.
The buoyant force on an object is affected by the density of the fluid it is immersed in and the volume of the object. According to Archimedes' principle, the buoyant force is equal to the weight of the fluid displaced by the object. Therefore, if the object is more dense than the fluid, it will sink, and if it is less dense, it will float.
Positive lift is the upward force generated by an airfoil, such as a wing, when it moves through the air. This lift is a result of the difference in air pressure above and below the airfoil, with higher pressure below and lower pressure above. This creates a net upward force that allows an aircraft to fly.
Buoyancy and positive lift are both examples of the same principle at work - the difference in pressure between two surfaces. In the case of buoyancy, it is between the top and bottom of an object in a fluid, while in the case of positive lift, it is between the top and bottom of an airfoil moving through the air. Both allow an object to float or fly by creating an upward force that counteracts the weight of the object.
Engineers use their understanding of buoyancy and positive lift to design objects that can float or fly. For example, in ship and submarine design, engineers must consider buoyancy when determining the shape and weight of the vessel to ensure it stays afloat. In aircraft design, engineers use airfoils and adjust their shape and angle to generate the desired amount of positive lift for the aircraft to take off and stay in the air.