Gerrard

No n does not change in this situation.

Why does is assume n and T are constant. For example, if you have a balloon with 10PSI at 25 C and a volume of 20L. If the temperature goes to 35 C, then you simply put in the changes into the equation right? The temperature of 35C and any potential pressure change to calculate work.

We all know this classic equation Work=-pressure external*delta volume and Pressure*Volume=#molecules*R(constant)*Temperature Can I rework the equation to be Work=-pressure (external)*delta (#molecules*R(constant)*Temperature/Pressure)

Finally someone with useful info rather than conspiracy. Now let’s create an Ronan point like structure. looks like two of the four walls collapsed. Why didn’t the other two walls collapse? I’m thinking to use wooden walls with paper joints. Just enough to hold it up. I have some sort of an idea now. Thanks.

I'd say they will accept the facts from a real demonstration rather than a computer simulation and reports. Seeing is believing.

Still I think it is a project for general education. According to a poll, 53% of Americans believe that there was some sort of a conspiracy. That's pretty significant and may be a gateway conspiracy for other hard conspiracy beliefs.

It doesn't have to be an exact scale model. Only that the damage occurring on sections have to be proportionate (1/9 of section) and the structure must be square or rectangle. When I said scale model, I didn't mean exact, just similar. Perhaps I shouldn't have used the word scale. Why not debunk any conspiracy theory? Why use a computer model when you demonstrate it in real life. A real life demonstration rather than a computer simulation? If so was it documented? If so can you provide a link to it?

how About a steel structure where the welds are very weak? And then heat the steel with a blow torch to weaken the steel? a million euros is a lot of money. Why would eat up most of the of the money? i have access the welders and mills. How was such a task achieved in the past? has someone already make a model of something similar

Any ideas? Why criticize? Why no constructive ideas?

I started out using paper structure. The material of construction can be anything as long as the density is consistent throughout the structure. Also there is a mast in the top. I tried burning the top area, but that didn’t work. I made one with denser wood. divided the section into two parts, the small top part and the large bottom part. I dropped the small part from 3.7 meters into the big part. (It was said that the section burned out and the top of the building collapsed on the bottom part). That didn’t work. I tried cheating and dropped the wood onto the bottom part made of paper. That also didn’t work.

Computer model won’t be accepted. Only if the help contributes to winning the challenge

An open contract is legally binding when one starts to carry it out and that includes one asking how to do it in this forum. If he doesn’t pay, the court will force him. How can you do it with just a model?

Anders Bjorkman has put out an open contract for a 1 million euros to create a scale model simulation of the trade tower collapse. I’ve been trying to recreate it but unsuccessful so far. How do I create a pancake collapse?

When the pump is not pumping, the flow is because of the fluid inertia that was obtained when the pump was pumping. Like a car when you accelerate to 60mph and then you let go of the accelerator, the car will still move 60mph even thought there are no forces being applied assuming no friction when the pump is pumping it moves the fluid because of pressure gradient

“If the pump can create suction, there will be very little” how do you suppose a pump works if it doesn’t create a pressure difference to create flow?

Yes just like a propeller plane. The explanation was already given on how that works. An explanation on how imbalanced forces are applied to rockets was also explained. Are you saying these explanations are wrong? Are you saying that pressure is not a potential energy? Are you saying that pressure gradient force is incorrect as well as the equation to calculate it?

Force is provided by pressure gradient force and is calculated as below: the pump merely creates a pressure difference and then pressure gradient force takes over. pressure differential is a potential energy like gravity. When you drop a ball from a height, gravity provides the force and there is no opposite force on you. The pump is like a person climbing stairs to gain height giving rise to gravitational potential energy. When you drop the the ball, there is no opposite force on the person dropping the ball. the pump creates a pressure differential giving rise to pressure gradient potential energy. having said that, there may force on the pump due to imbalanced force just like on the tote. Perhaps Bufofrog is correct?

The pump merely provides negative pressure or suction. Why wouldn’t there be an imbalanced force in tote? Like in a balloon, there is negative pressure in the atmosphere compared to the balloon. Let’s say you had a vacuum at the end of the balloon, the balloon would still move forward. The vacuum merely creates additional negative pressure? In other words, there is pressure pushing equally on all sides of the container except for the side with the hole. How is the scenario different if there was a pump attached? An astronaut throwing rocks is not really a good example because the pump only creates a pressure difference and pressure gradient force is what actually moves the fluid right?

Wouldn’t the imbalanced for be felt in the tote. The pump causes the fluid in the tote to come out the side. The fluid is pushing on all side of the tote equally except the side with the hole. Thus there should be an imbalanced force?

The question was pretty clear. Let’s start with the first hypothetical scenario. I have a tote full of water. I use a pump to remove the water from the tote and add it to a lake. The flex hose is connected from a valve on the side of the tote to the pump. The flex hose has a lot of slack. When the pump removes the water, is there a force on the tote in the opposite direction of water flow? Would there be tension on the flex hose? Let’s say the draw side of the pump is 0 psig. Bullfrog understood the original question and stated that there wouldn’t be force on the tote. Do you agree? I didn’t say that conservation of momentum doesn’t exist. I stated it is incorrect to apply it to rockets in the manner stated by others.

Yes it holds where it is required. As I explained, momentum is conserved by pressure gradient force, not the rocket. How can you answer my question when something simple like conservation of momentum cannot applied correctly?

I disagree with the conservation of momentum effect for the following reasons. As I have stated before in this thread, the rocket is not required to "push" or provide a force for the exhaust to overcome it's inertia. The external force to change the exhaust's inertia comes from pressure gradient force. Therefore, conservation is always conserved without the rocket in the picture. Pressure gradient force is a potential force like gravity. When you drop a ball from your hand from a height, the ball does not need your hand to apply a force in order to conserve momentum as gravity provides the force for the ball to overcome it's inertia. Using the propeller example, the propeller creates high pressure behind to propeller. If you were to use a very strong vacuum to dissipate the pressure being built behind the propeller, pressure cannot build behind the propeller and therefore will not move towards the front of the propeller in order to create movement. If a person standing on a skateboard were throwing medicine balls and I use a very strong vacuum to dissipate pressure in the area where the balls were being thrown, or I was catching the balls and throwing them aside, the person on the skateboard would still move. It is because the person on the skateboard is providing the force, hence momentum must be conserved. Similarly, if the propeller was actually throwing the air behind it, there would be still movement even in the presence of the strong vacuum. So therefore, the conservation of momentum effect is not correct.

Here’s another source https://howthingsfly.si.edu/propulsion/rocket-propulsion “If you fill a balloon with air and hold the neck closed, the pressure inside the balloon is slightly higher than the surrounding atmosphere. However, there is no net force on the balloon in any direction because the internal pressure on the balloon is equal in all directions. If you release the neck of the balloon, it acts like a hole, with no surface area for the internal pressure to act on. There is now an imbalanced force on the balloon, and the internal pressure on the front of the balloon is greater than the internal pressure on the back of the balloon.” NASA sight doesn’t explain it well but the vector diagram I posted from them show exactly this. They can’t all be wrong

There's a little more to it than simply action and reaction by throwing mass. In fact the balloon or rocket isn't throwing mass, the mass moves because of pressure differential. https://www.ias.ac.in/article/fulltext/reso/016/01/0065-0068 "The pressure exerted by the air molecules on the walls of the rubber balloon is balanced by the tension/stress induced in the material of the balloon, plus the atmospheric pressure acting on the surface of the balloon. The pressure exerted on the interior walls of the balloon by the air in it, Pair, is the same across any given area of the balloon. Pair is the value of the pressure inside the balloon above the atmospheric pressure value. See Figure 1. As a result the pressures acting on geometrically opposite walls of the balloon balance (cancel) each other. Hence the net force acting on the balloon is zero. The air starts escaping through the mouth of the balloon. Since there is no wall now at the mouth of the balloon, no pressure is exerted by the escaping air over that area. Hence less force is exerted on that side of the balloon. This causes imbalance in the forces acting on the interior walls of the balloon. Net unbalanced force is now acting on the area diametrically opposite the mouth of the balloon. This unbalanced force is the thrust Tb , acting on the balloon, which moves/propels the balloon in its direction. The magnitude of the thrust is equal to the force that would have been exerted on that area had there been a wall at the mouth of the balloon."

You had stated : "If there is a tote that you close with a cap then you would have a tote that is filled with air. Inside the tote the air pressure would be 14.7 psi (lbs/in^2). Out side the tote the air pressure would be 14.7 psi. This means that inside and outside would have 14.7 lbs of force on each square inch of the tote container. If I pull a vacuum and lower the internal pressure to 12.7 psi, that would mean there would be a 2 lb force on each inch of the tote pushing in on the surface. If the tote was glass nothing would happen, there would simply be a constant force of 2 psi on the glass. If the tote was a pliable plastic the force would push in the walls of the tote. The tote would be compressed in size until the pressure inside the tote was raised to 14.7 psi and then it would be in equilibrium and it would stop compressing. Since the forces are felt on all sides of the tote there would be no force in a particular direction, so the tote would not move." Since my question was about a pump removing contents of the pump using negative pressure, I presumed that when you pull a vacuum and lower the internal pressure, you are removing contents from the tote with the pump. Opening a valve to the flex hose and pump is putting a hole in the tote. So when you open a hole in the tote, the force vector on the hole side (Action) is smaller than the force vector on the reaction side (reaction). The force vector being created by the internal pressure of the tote. Hence an imbalanced force causing movement. https://www.grc.nasa.gov/www/k-12/rocket/TRCRocket/rocket_principles.html