Balloon Definition and 468 Threads

Homework Statement Hi, I'm currently trying out a practical problem where I'm trying to calculate the energy present in an inflated balloon, as well as what happens to that energy once the air is let out from inside the balloon. The balloon is attached to a car, so that as the air escapes it...

One of my hobbies is launching high altitude weather balloons carrying video cameras and scientific instruments to record various environmental parameters at high altitude — 90,000 to 100,000-feet. I'm planning another project and I was wondering how much pressure is being exerted inside my...

Dear readers, For a Biomedical Engineering project I have to develop a model for the respiratory system of a neonate. This will be done by using pressure/volume data of the lungs. To model these, I would like to use a rubber balloon. However the calculation are more difficult than I thought...

Homework Statement 1. Explain why a balloon sticks to a wall after being rubbed on your shirt (remember the wall is not metal and does not have "free" electrons") 2. Include a balanced force diagram that includes the electrical force and gravitational force (assume electrical force is twice...

1. An empty spherical weather balloon with a mass of 5 kg has a radius of 2.879 m when fully inflated with helium. It is supposed to carry a small load of instruments having a mass of 10 kg. Taking air and helium to have densities of 1.16 kg/m^3, respectively, what will be the acceleration of...

Homework Statement The helium in the cylinder has a volume of 6.0 × 10^–3 m3^-1 (0.0060 m^3) and is at a pressure of 2.75 × 10^6 Pa. (i) The pressure of helium in each balloon is 1.1 × 10^5 Pa. The volume of helium in an inflated balloon is 3.0 × 10^–3 (0.0030 m3). The temperature of the...

Sorry to bother you all with another-of-its-kind (most probably unsatisfactory) analogy that I came up with myself (error detection sirens should be blaring now) to better understand "energy" in cosmological expansion, but I just can't rest until I find out how (in)accurate it is from you all. I...

Homework Statement You are blowing air into a balloon at a rate of 4*pi/3 cubic inches per second. (The reason for this strange-looking rate is that it will simplify your algebra a little bit.) Assume the radius of your balloon is zero at time zero. Let r(t), A(t) and V(t) denote the radius...

Homework Statement A 124-kg balloon carrying a 22-kg basket is descending with a constant downward velocity of 23.5m/s A 1.0-kg stone is thrown from the basket with an initial velocity of 14.8m/s perpendicular to the path of the descending balloon, as measured relative to a person at rest in...

People often use the expanding balloon with galaxies on the surface to represent the expansion of space. But this view doesn't show how this expansion works in 3d and it doesn't show how gravity comes into play. Instead of putting the galaxies on the surface of the balloon all we have to do is...

Homework Statement Take an elastic balloon of volume V in vacuum. The surface of the balloon has tension T. Find the pressure inside the balloon in terms of V and T, then combine this to the ideal gas law to find an expression for V. Homework Equations See below The Attempt at a Solution I...

Homework Statement A helium balloon is used to lift a load of101N. The weight of the envelope of the balloon is46.5N and the volume of the helium when the balloon is fully inflated is31.5m3. The temperature of the air is 0°C and the atmospheric pressure is 1.00 atm. The balloon is inflated with...

Hello, I was learning about Avogadro's Law and trying to find some real-life example of it. It mainly states that: For a given mass of an ideal gas, the volume and amount (moles) of the gas are directly proportional if the temperature and pressure are constant. So let's say I have a balloon...

I'm trying to make a blimp robot, I want to get into the drone-building hobby but right now a quadrotor is too expensive, plus I want to be a bit more original. I need something that I can make the balloon out of that won't leak (so I don't have to refill it often) and reasonably durable...

Hi all, So my question is, could you use a weather balloon to assist with escaping the atmosphere and attaching a rocket to take it the rest of the way, and we're talking a really small payload obviously. Would the weight of the fuel/rocket weigh down the balloon enough to significantly...

If I heat a rubber balloon filled with helium slowly and if the balloon is fully expandable and (the balloon) can be assumed to require no energy in its expansion,what type of thermodynamic process is taking place? Is it isobaric? Since the balloon expands the pressure exerted by the gas on...

Homework Statement A hot-air balloon has a volume of 2000 m^3 and generates a lift of 2720 N (assume the outside temperature is 20◦C with an air density of 1.2 kg/m^3). A)What is the density of the air inside the balloon? B)How many moles of air are inside of the balloon (the molecular mass of...

Homework Statement At an altitude of about 10 km, the temperature of the Earth’s atmosphere is roughly -50°C and the air pressure is around 16 kPa. (Assume ideal gas) How many kilograms of hydrogen gas (H2, molecular mass 2g/mol) should be put in a balloon to fill it to 2000 m3?What is the...

Homework Statement Assuming normal pressure and temperature outside, and normal pressure inside, what should be the inside temperature (in Celsius) if the hot air balloon has diameter 17 meters and carries 446.3 kg load? (Except the mass of air inside, everything else is included in the...

Has anyone here ever asked these questions about the balloon analogy? 1. If the universe actually was the 3D surface volume of an expanding 4D hypersphere, how big would the radius be? (let the radius of the observable universe be 46.25 billion light years) 2. How fast is it expanding...

I've seen the example when people say the universe is expanding like the surface of a balloon. You have dots on that balloon which are galaxies and as you blow up that balloon they grow further away from each other. If the universe is expanding equally isn't there a centre which is constantly...

Homework Statement An initially deflated and flat balloon is connected by a valve to a storage tank containing helium gas at 1 MPa at ambient temperature of 20°C. The valve is opened and the balloon is inflated at constant pressure of 100 kPa (atmospheric pressure) until it becomes...

Hello PF, Can anyone recommend a set of governing equations for the design of a simple elastomeric balloon that will expand to a "hotdog" shape when inflated to a certain pressure? I have the stress-strain curve for the material, I know what pressure I need to inflate it to, I just can't...

Several companies have put forward plans for suborbital aircraft that use bouyancy to reach the edge of space. In fact, balloons can ascend to over 60,000 ft. Would it be possible to design an aircraft that uses bouyancy to ascend and then somehow convert to a glider to land unpowered, using...

Why is it hard to get the air through the balloon when you first fill the balloon ? But after inflating it z bit it becomes easier to further inflate ?

Hi, I came across this question in a physics review pamphlet: Homework Statement A balloon for a county fair is designed to carry four 100-kg passengers when it is expanded to its maximum volume. The designers assumed the balloon would operate in ordinary spring temperatures. If, on...

did anyone observe that a balloon gets cold when stretched quickly,why?

Any reason why the balloon could not be substituted for a turbine to make a practicle flying device . One that could have comercial use. http://www.presentsformen.co.uk/science-museum-balloon-copter-prod9413/?gclid=cpdtrkvg074cfcpmtaodrnoa5g

Homework Statement A Mylar balloon is filled with helium to a pressure just greater than 1.00 atm on a day when the temperature is 30°C. It is released near sea level (an altitude of 0.00 meters). Using the Standard Altitude/Density Table below, estimate the maximum altitude reached by the...

Homework Statement A hot air balloon with a total mass of 7000 kg carries a gondola (or basket) which includes 1000 kg of sand bags fixed to the outside. While hovering at a fixed altitude, sand starts leaking out of thebags at a rate of 50 kgs-1. Determine the velocity of the balloon at the...

I am teaching Physics and I'm not looking for help for a particular homework problem but on a class. Sorry if this should be in the homework sections. When I park my car where the sun only hits one side and measure my tire pressure later I find the tires on the sun side have a higher...

Homework Statement A soap bubble is blown with a relatively short drinking straw of diameter d, and then the bubble is left to deflate through the same straw. In one case when the diameter of the bubble was D the time during which the bubble deflated was 8 seconds. Estimate the time during...

Homework Statement We were given homework to explain how this balloon pressure experiment works. You basically take a plastic bottle and make a small hole in it near the base. You then push a balloon in through the top and pull it over the bottle opening. You then blow it up so that it inflates...

Homework Statement A hot air balloon with V = 500 m^3 is floating in the air without moving. The air outside the balloon has a density of 1,20 kg/m^3, and the hot air inside the balloon has a density of 0,75 kg/m^3. Calculate the total mass of the hot air balloon. Homework Equations...

Homework Statement The mass of a hot-air balloon and its cargo (not including the air inside) is 200kg. The air outside is at 10C and 101kPa. The volume of the balloon is 400m^3. To what temperature must the air in the balloon be warmed before the balloon will lift off? (The density of air a...

Homework Statement Any floating homogeneous balloon in a planar uniform wind current will always "tend" to present to the wind flow a section of maximal drag. 2. The attempt at a solution I have three possible solutions to this "problem": 1- Speed gradient justification: When an object...

Homework Statement Two balloons A and B are filled with He gas. They have identical radii of 10 cm. The balloons are made with rubber so that they can be charged by rubbing against hair. They are held together with insulating strings, whose mass and charge can be ignored for this problem...

Homework Statement A hot air balloon of mass 425 kg ascends from the ground level and accelerates at a rate of 1.25 m/s/s for 25 seconds. How much work is done by the upward buoyant force on the balloon? (conceptual) A certain amount of work W is required to accelerate a car from rest to a...

Homework Statement A boy is on top of a 12 m tall building. He throws a water balloon horizontally, releasing it at a height of 1 m above the top of the building. The water balloon is thrown at 30 mi/h and is aimed at the balconies of an apartment building across the street, 18 m away...

Here is the question: I have posted a link there to this thread so the OP can view my work.

Homework Statement You and your roommate plot to drop water balloons on student entering your dorm. your window is 20m above the side walk. You plan is to place an x on the side walk to mark the spot a student must be when you drop the balloon. You note that most student approach the dorm at...

Homework Statement A balloon takes 0.22s to cross a 1.3m high window. From what height above was it dropped? Homework Equations None. The Attempt at a Solution

Homework Statement A balloon stands upright in a stationary truck. The truck then accelerates forwards. What direction does the balloon move in? Homework Equations Just Newton 1&2. The Attempt at a Solution 1) A Free body diagram on the balloon. We know the balloon accelerates...

Hi everyone I had this very silly question pop up that unfortunately I cannot find an answer to myself. If an object - say, a hot-air balloon - flies at a low altitude above the Earth, it will of course remain above the same spot; you could I guess say that it rotates together with the Earth...

Two new uninflated balloons do not attract or repel each other. But after blowing them up, they repel each other and stick to the wall, without having to be rubbed against hair or anything else. Why do balloons gain charge simply by being inflated? It seems that the newly-inflated balloons...

Hi guys, Say we have a balloon, not completely inflated like in the sketch picture below. I would like to come up with a set of equations connecting between the increase in pressure inside the balloon and the change in the following dimensions as a result: 1. "neck" length (shown as 40mm...

Pressure vs. "neck" shortening of a balloon I swear this is not a homework question :approve: The purpose of this question is to simulate the shortening of the cervix ("neck") as a result of the increase of pressure -> volume of the female womb. I would like to come up with a set of...

Homework Statement A balloon behaves such that the pressure is P = CV3 where C = 100 kPa/m3. The balloon is blown up with air from a starting volume of 1 m3 to a volume of 3 m3. Find the work done by the air. Homework Equations W=∫PΔV... something to do with integrating to find the...

Hello. I've regained a certain interest in lighter-than-air-craft recently. To satisfy this interest, I wish to construct a small, rigid, unmanned, moored, hydrogen balloon within the bounds of reason. I'm most definitely not an engineer to any extent, and as such, I have many questions...

An air balloon of mass M descending down with acceleration 'a'.A mass m is dropped out of it and the acceleration becomes a upwards.Find m in terms of M,a... The right answer is 2Ma/(g+a) The explanation I was given: The mass out of the balloon now has a+g acceleration. (How could it be when g...