Balloon Definition and 484 Threads

Hi i have this question: A balloon is filled with helium gas which weighs approximately one-seventh of what air weighs under identical conditions. The balloon has a diameter of 10 m and carries two people, each weighing 70 kg. Assume the density of air is 1.16 kg/m3 and neglect the weight of...

Homework Statement Imagine that 9.9 g of liquid helium, initially at 4.20 K, evaporate into an empty balloon that is kept at 1.00-atm pressure. What is the volume of the ballonat the following? (a) 23.0 K(b) 299 K Homework Equations PV=nRTThe Attempt at a Solution I converted th 9.9g of...

Question from my homework. I'm not exactly sure what I am doing wrong, and it is bugging me. I hope this post is in the right forum. Imagine that 9.9 g of liquid helium, initially at 4.20 K, evaporate into an empty balloon that is kept at 1.00-atm pressure. What is the volume of the balloon at...

Homework Statement The rate of change of the altutide of a hot air balloon is given by r(t)= t3 - 4t2 + 6 for 0 ≤ t ≤ 8. Which of the following expressions gives the change in altitude of the balloon during the time the altitude is decreasing? a. ∫r(t)dt when t goes from 1.572 to 3.517...

I need suggestion on how to make a balloon powered Hovercraft. THE AIM: the aim is to make the hovercraft travell a displacement of tleast 3 meters.. THE CONDITIONS: 1. it has to be powered by no more than a single party balloon. 2. the base of the hovercraft must be a CD. (the...

Homework Statement A hot air balloon has a volume of 2000m^3, and air is always at atmospheric pressure due to large opening. What is the mass of the air if the temp is 120*c. Assume a molecular weight of 28.8g/mol for the air) Homework Equations PV=nrt The Attempt at a Solution...

I feel kinda stupid asking this, since I have a bachelor's degree in physics. But, here it goes: I'm doing a thought experiment on my own (i.e., not a homework problem) for a hypothetical vacuum airship. I've determined the following quantities: V_displaced = 15 m^3 m = 13.5 kg F_net =...

Homework Statement If a stone is dropped over the side of a hot air balloon that is rising at 3 m/s and it strikes the ground 1.5s later, from what height above the ground was the stone dropped Would V1 be 3 m/s or 0.. I'm really confused.

Homework Statement The air inside a hot-air balloon is heated up from a density of 1.25 km/m^3 and a temperature of 27 degree celcius until the balloon begins to float . During the heating process , some air escapes from the balloon and the pressure inside the balloon remains constant at just...

Homework Statement A spherical balloon is inflated to a diameter of 36 cm. Assuming that the gas in the balloon is of atmospheric pressure (101.3 kPa) and is at a temperature of 20°C. (a) How many moles of gas are in the balloon? (b) If 21% of the molecules in the balloon are oxygen...

Homework Statement A balloon rubbed against denim gains a charge of −2.0 μC. The Coulomb constant is 8.98755 × 109 N · m2/C2. What is the electric force between the bal- loon and the denim when the two are sepa- rated by a distance of 6.0 cm? (Assume that the charges are located at a...

Helium balloon "centrifugal" force Homework Statement Assume that you are driving down a straight road at a constant speed. A helium-filled balloon is tied to a string that is pinned to the front seat. Which way will the balloon swing when you apply the brakes? Explain why. Homework...

Hi, Not sure if this is asked in the right section, but I am doing something which involves moving a small car, and I am trying to make predictions from an air resistance perspective. I'm trying to come up with a rough expression for the drag force on a balloon as it deflates. I've started with...

Hey, I'm looking for the optimal antenna to transmit in the 900 Mhz range from a high altitude balloon. The transceiver I have says it is capable of 40 miles LOS with a 15 dBi antenna. Can achieve this? Can I just hang say a 100ft wire from the bottom of the balloon? Do I need a different...

As you look out of your apartment window, you see water balloons falling past. You measure that the balloons are visible (going past the window)for a time t, and the vertical length of your window is L_w. assume that the water balloons were dropped (rather than thrown downward). Determine then...

Homework Statement I'm trying to find the buoyant force on a hot air balloon. The mass of the displaced fluid is 2800 kg and the acceleration is that of gravity, (let's say 10 m/s^2). Homework Equations F=ma The Attempt at a Solution I think that you can just multiply these...

Homework Statement How many electrons would it take for a typical balloon to stick onto a ceiling? State assumption for ceiling size or balloon size if necessary. Homework Equations e = 1.60 x 10 ^ -19 C q = Ne The Attempt at a Solution I thought that it took only one electron for...

Picture a helium balloon on a string. I hold one end of the string, and the balloon rises until the string is taut. With the balloon hovering at its location, and with tension on the string, I cut the string near the bottom. The balloon will rise, taking the string with it. So, the question...

I am befuddled over how to calculate the force acting on a surface point of a deformed balloon (filled with water or air). I have drawn a picture to help illustrate. I have written a small program in c++ that uses the Runge-Kutta algorithm to simulate simple physics systems, like networks of...

I wonder if it is possible to make a helium ballloon to Levitate in the air without touching the ceiling? Something like this. http://www.youtube.com/watch?v=7kI-_MhnyzE" Thanks,

BALLOON PROBLEM. please please help :) Homework Statement I need to find the volume of a helium balloon, and 9 paperclips can sit on it so it doesn't float away (.004kg). Density of He=.18; density of air=1.29; mass of balloon=.0116kg. Homework Equations Free body sum of equations...

Homework Statement A hot-air balloon achieves its buoyant lift by heating the air inside the balloon, which makes it less dense than the air outside. Suppose the volume of a balloon is 1900 m3 and the required lift is 2500 N (rough estimate of the weight of the equipment and passenger)...

How much energy (Watts?) would be created by a balloon that was released under water? I am picturing a scuba diver's inflatable vest (a BC) that is suddenly inflated (assume zero air inside to begin with). Or more accurately if you have ever seen a free-diver who swims down a few hundred feet...

I want to model the motion of balloon filled by a human not helium or any other gas. what would be the equations? I know the air would've some mass so if I throw the balloon up that would f=ma ? distance = vt? when a balloon comes down its downward motion is much slower say compare to a...

Think about the dimensionality of a balloon with surface waves. Say these waves are of small amplitude compared with the radius of the balloon. Two coordinates label points on the balloon and a third labels radial position. Creatures who lived on the surface could make measurements that...

Suppose I inflate a balloon on the moon and then let it go. What would happen? Would it: 1) slowly release air and fall to the ground of the moon or 2) release air faster and fly away faster than on earthMy answer: I reasoned that the key to this question is the pressure difference, for the...

While reviewing the Archimedes Principle with my AP students using ConcepTest questions from the Wilson, Buffa, Lou text I came across an answer that I believe is incorrect. The question was the second question in a series of questions about a helium filled balloon. The first question asked...

Homework Statement Suppose we make a circular hole 2 millimeter in diameter in a balloon. Calculate the initial rate at which oxygen escapes through the hole (at 0° C), in number of oxygen atoms leaving the balloon per second. Homework Equations 1/4 n*A*v The Attempt at a Solution...

In the problem I am working a shipping crate is underneath the water, the dimensions of the crate are given. They tell you that when a balloon is inflated to a radius of 1.3m the crate starts to rise. What is the mass of the crate? FB = Wfluid P= F/AI calculated the buoyant force acting on...

[b]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 An empty rubber balloon has a mass of 0.0122 kg. The balloon is filled with helium at a density of 0.179 kg/m3. At this density the balloon has a radius of 0.467 m. The acceleration of gravity is 9.8m/s2. If the filled balloon is fastened to a vertical line, what is the...

Homework Statement assume the balloon is a spherical shape whose radius is 2.5m and total mass of 15 kg a) what is the initial upward acceleration of the balloon when it is released from sea level Homework Equations The Attempt at a Solution i know the volume of a sphere is...

1. A 1.10 balloon is filled with helium gas until it becomes a 24.0 -diameter sphere. What maximum mass can be tied to the balloon (with a massless string) without the balloon sinking to the floor? (in grams) 2. F = ma pA = p*pi*r^2 3. radius = 0.12m F_air = p*pi*r^2 = 4583N...

Homework Statement If the balloon in the diagram drawn below is accelerating upwards at 0.40 m/s2, calculate the tension in each piece of rope. Assume that the rope has no mass. http://img261.imageshack.us/img261/964/capture2gm.png http://img261.imageshack.us/img261/964/capture2gm.png...

I was watching a program "what would happen if" (or something along that line) in NatGeo and was stunned by what i saw in it. This is the situation. Several helium balloons are suspended from a car's roof panel through strings (interior of the car). When the car decelerates, what direction do...

Homework Statement What is the magnitude of the acceleration of a rising hot-air balloon if the ratio of the air density outside the balloon to that inside is 1.25? Neglect the mass of the balloon fabric, the basket and it contents. I don't know how to do a rho so "p" will be rho for density...

Homework Statement In the figure below, a 74 kg man is on a ladder hanging from a balloon that has a total mass of 260 kg (including the basket passenger). The balloon is initially stationary relative to the ground. The man on the ladder begins to climb at 2.5 m/s relative to the ladder...

Homework Statement Starting from rest, a 64.0 kg person bungee jumps from a tethered balloon 65.0 m above the ground. The bungee cord has negligible mass and unstretched length 25.8 m. One end is tied to the basket of the balloon and the other end to the person's body. The cord is modeled as a...

I debated on putting this in the thread a couple down from this, but since they are two totally different questions, I figured this should be okay. After seeing this on the news today some of my co-workers were talking about if the balloon could even lift the child. They had seen an episode...

Homework Statement Calculate the balloon lift if it were submerged in water. Volume of balloon (sphere) = \frac{(5^3)*(pi)}{6} = 125pi/6 The balloon is filled with hellium. Pfluid (water) = 64.2 lb/ft^3 Homework Equations Lift = Volume * gravity * (Pfluid - Pbody) \frac{Pfluid}{Pbody} =...

I'm trying to calculate the acceleration of a high altitude balloon at different altitudes. In excel I've got the temperature, air pressure, and air density for a given altitude (thanks to NASA). Right now I am calculating the net force on the balloon with: Fnet= Fb-Fm Fb = Buoyant force =...

1. Experiencing a constant horizontal 1.10 m/s wind, a hot-air balloon ascends from the launch site at a constant vertical speed of 2.50 m/s. At a height of 205 m, the balloonist maintains constant altitude for 10.0 s before releasing a small sandbag. What is the horizontal displacement of the...

Since the SABLE project broke on slashdot and youtube, I've been kind of keeping an eye on the tech, and science these average Joe's put into it. (I'm one of these average Joe's). For those not familiar what these projects, here's an overview. The SABLE and BEAR projects basically strap a...

My teacher assigned a project in which we have to build a device that will launch a water balloon at least 200 yards, the only restriction being that the use of compressed air is prohibited. I have already thought of several designs using a slingshot or catapult. It would be wonderful to be...

Homework Statement A hot-air balloon has just lifted off and is rising at the constant rate of 2.3 m/s. Suddenly one of the passengers realizes she has left her camera on the ground. A friend picks it up and tosses it straight upward with an initial speed of 12 m/s. If the passenger is 2.5m...

A balloon contains 3.90 m3 of argon gas. It is slowly heated at a constant temperature so that its volume triples. If the gas does 3.00 kJ of work in the expansion, what was the initial pressure in the balloon? Isothermal Change of an Ideal Gas: W= -nRT(ln Vf/Vi) PiVi=PfVf= nRT...

A hot air balloon has just lifted off and is rising at the constant rate of 1.30 m/s. Suddenly, one of the passengers realizes she has left her camera on the ground. A friend picks it up and tosses it straight upward with an initial speed of 9.40 m/s. If the passenger is 2.30 m above her friend...

A drug delivery infusion pump is made out of thick synthetic rubber and has a very small outlet. The balloon pump is filled with 500mL liquid drug and is now inflated into a ball shape. The drug will exit from the very small outlet at a nearly (but not always) constant flow rate of 5mL/hr (takes...

A drug delivery infusion pump is made out of thick synthetic rubber and has a very small outlet. The balloon pump is filled with 500mL liquid drug and is now inflated into a ball shape. The drug will exit from the very small outlet at a nearly (but not always) constant flow rate of 5mL/hr (takes...

Hello physics forum, I'm interested in modeling the pressure wave created due to the rapid inflation of a balloon. Say I'm able to rapidly increase the temperature of the air in a balloon, faster than it can equilibrate its pressure with the outside air. It will expand to satisfy PV = T...