Air Definition and 1000 Threads

i have a pre made tank approx dimemsions 3x3x3 feet the thickness of tank walls appear to be 3/16 to 1/4 inch thick. with a 1foot square opening on top for filling this opening had a raised "wall" approx 2inches. tank is used to collect used oil for shop heating. (this tank looks like a...

In this clip the mythbusters are investigating projectile motion at a firing range: Using the fact that the bullet fell approximately 1 inch as it traveled 100 feet, I predicted it should travel 600 feet down the firing range before hitting the ground from a height of 36 inches. Instead, it...

What defines how much energy we could store in some gas by compressing it to a certain volume by applying a certain pressure? The compessability coefficient? Is there some gases which allow to store more energy than air? Which gas has the largest compressibility coefficient?

Homework Statement [/B] The shape of a car windshield is approximated in the figure below; its length is 2.0 ft and height is 1.5 ft. Obtain an equation of the windshield shape r as a function of θ, r(θ), in the polar coordinate system shown in the picture. When the car moves at 55 mph...

< Moderator Note -- thread moved from General Physics to Homework Help forum > If a ball is projected vertically upwards say with a velocity V. Case 1: Without air drag Case 2: With air drag What will be the difference in v-t graphs and the motion of the ball Air drag D=bv (b is a constant,v...

△Work = △KE + △PE Work = Force x Distance W=F△x Pressure = Force/Area W=PA△x Volume=Area x length W=PV Work = Pressure x Volume KE=(1/2)mv^2 Density = mass/volume mass = density x volume m=DV KE=(1/2)DVv^2 (work done by air pressure?) PE=mgy PE=DVgy (work done by gravity and air pressure??)...

How does weight affect air resistance? [i.e A heavy feather falling v.s a light one}Please be simple

Hi, everyone! I have a question: if we quickly fill a cylinder with steam from one end and with hot air from another end, both at atmospheric pressure and equal volume, with hot air 4 times hotter than steam, and then immediately seal that cylinder -- will pressure change as steam and hot air...

1. A parachutist of mass 62 kg is falling at 55 km/h when her parachute open. She then falls 24 m in the next 2.0 seconds. Find the force of air resistance acting on the parachute during those 2.0 seconds.2. Could I just find the force of friction?3. I found out what the force would be if not...

If you have a tank with compressed air. Say this tank is a cube of 1x1x1m. One of the walls are "mobile" but sealed so no air can excape. A spring on the outside is pushing on this wall so it will remain in its position at for example 10 bar pressure inside the tank. Now, atmospheric air has a...

I need create a math model to predict the temperature of a copper pipe with hot air flowing through based on the temperature of the air, properties of the air and copper, and the surface area of contact between the air and the pipe. The pipe will start cold but I will be looking to the...

Homework Statement What angles should an arrow be launched if it leaves the bow @ speed of 60 m/s and is trying to hit a target that is 150 m away? Assume target is same height as bow. Suppose the arrow is fired at an angle of 30 degrees & misses the target & hits the ground 1.8 m below from...

Hello all, this is my first post here, so please excuse me if there are any mistakes or important information is left omitted. Now, my problem is quite intricate and specific so I will be thankful for any information I can get. Using Excel, I am looking to model the volume flow of air through...

I'm working on a kinda-sorta confidential device. I would like to know how much psi is required to lift approx. 400 pounds 120m (about 393ft and 8 13/32 inches) into the air. The thing I'm working on is still in the designing stage, so don't worry about the specifics of individual thrusters and...

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...

Hi, I am wondering if anyone can help me out with this, I'm looking to create 130.5 PSI of Water pressure for 15-20 seconds. If I were to pressurize an air chamber what size/volume would be required to achieve the above? Or would it be better to directly pressurize a chamber with water...

I was hoping to find out how long it takes for 1000 ml water to heat up to air surrounding air temperature - is there a general equation that can be used to work this out? For example, 1000 ml of water = 14 deg C; surrounding air temperature = 18 deg C. In more detail the water container volume...

We have a solid cube with some mass that we fire as a projectile at some angle. The cube is launched in such a way that two of the faces are perpendicular to the initial velocity vector. Assuming there is air resistance, would the cube change its orientation while it flies, even if the mass is...

Homework Statement Part A: Calculate how many mocules per cubic metre in air at 27°C and at a pressure of 1.1 atm (1atm is 1.01 x 10^5) Part B: What is mass in grams of 2.4m^3 of this air. Assume that 75% of the air is N2 (with molar mass of 28 g/mol) and 25% O2 (with molar mass of 32 g/mol)...

Homework Statement An Astronaut on a spacewalk has an oxygen tank strapped to his suit. The oxygen in it is pressurised to 5 atmospheres (5x10^5 Pa), and the volume of the tank is 15 litres. a) The oxygen is pumped to his mouth at atmospheric pressure (1x10^5 Pa). What is the maximum volume of...

I need help with ideas on how to pump water our of a sump pump that is always filling up. Using a sump pump when the float is tripped is really load. I need something that quietly pumps the water out steadily while not using up huge power...but it needs to be quiet! I see these aquarium...

Homework Statement measure the velocity of sound in the air using tuning fork and a pipe closed at one end method a: End Correction involves applying a correction factor to the first resonant length based on the diameter of the tube used. method b: Second Resonant Length involves finding two...

Hello,just seeing if someone can help me on here,i have a rc glider measuring 2200 mm on the ground,when in the air it measures about 35mm. Can the the height be calculated from these measurements.

I've been trying to figure out this problem for hours my whole group and most of the class is stumped. We understand that we need to relate the equations of F=ma, Fd = (Cd*p*v^2*A)/2, Fnet=Fd-Fg. No data is given. The answer is a V=____ equation. Even just an answer to #1 would be very helpful...

Is there a formula covering this? (not including free fall/gravity) I have the drag coefficient, velocity and every other variable I think I would need for the object in particular.

An object with a mass if falling with a force that is equal to its own weight of 25 pounds. The air resistance causes a decelerate force equal to 1/2 the velocity of the object at any time. If the object falls from rest, what is the velocity of the object after 8 seconds? I'm just confused at...

Hello- First post here, I can't seem to wrap my head around this concept and how to overcome it. I read here: https://www.physicsforums.com/threads/air-lock-concept.83124/ that air's compressibility is what stops flow, why is this? I also read that a stronger pump (in a vehicle's fuel system...

Hello, I do not really know if this is the right place to post this message ... if it's not then I'm sorry I am looking for a valve that allows the flow of liquid but prevent air escaping out form let's say a sealed container ... Is there such a thing?

Air pressure decreases at a rate of 2.5 pascals per kilometer in the eastward direction. In addition, the air pressure is increasing at a constant rate with respect to time everywhere. A ship sailing eastward at 10 km/hour past an island takes barometer readings and records a pressure drop of 30...

This was an extra question in an exam I took today. The temperature of the air in the bottle remains constant. I know this has something to do with buoyancy and ideal gases since temperature was mentioned in the question, and I think I could have easily solved the question, had the submerged...

A water skier of mass m is pulled at a constant velocity v by a boat of mass M. Tension in the rope held horizontally by the skier is T. a) Find the total resistive force by the water and air on the skier. b) How much upward force does the water exert on the skier?What equation would I use to...

Homework Statement Neglecting air resistance, if you throw a ball straight up with a speed of 20 m/s, how far will it be moving when you catch it? Homework Equations None The Attempt at a Solution

If I took a hammer to each of the screens, which would crack first with a minimum amount of force? If I put a screen protector on it, would it change the answer of which one would crack first? I tried to pick two models which had similar frames. If the using different models actually makes it a...

I am trying to size an orifice to place on an outlet of an air vent line. The reason for this is that I am installing a noise suppressing muffler, but it is only rated for 300 psig. Since I am venting a line that will be pressurized to 1600 psig, I'd like an orifice restrictor in order to...

hello. I have to design and test a gas turbine that uses pressurised air as a project. however the problem is, I don't know where to start. can anyone please help me? do I start with the blades or the housing? I have seen some videos on youtube, but this is a university project and I think its...

Homework Statement Two students conduct physics experiments on a balcony 19.6 m above the street. One student throws a ball vertically downward at 14.7 m/s. At the same instant the second student throws a ball vertically upward at the sam speed. The second ball follows the same path as 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...

Homework Statement A helicopter is hovering 10m above the ground, weighs 6230kg and the rotors are 14,6m in diameter. Which speed does the air have that the rotors are pushing down? The Attempt at a Solution i really have no idea where to begin but the chapter has to do with impulse so i...

Hey guys! I'm doing a project and having a tough time deriving the equations to model it (Matlab (ODE/PDE) or Excel (cell/dv/dt)). I would love some insight/help etc! To start off there's a sealed rigid container which has a bellow attached internally and a valve. The inside of the bellow...

Hello all, I am currently installing a 4 station inflation system. My problem is that i do not want to lower the systems pressure when one or two of the stations are inflating. All 4 stations are fed by a global 120 psi feed. I want to maintain 5 gallons at 80 PSI at each station. To do...

i am doing a research about ionized air ,and i have little question how much electrical resistance ionized air have?

Hello, I apologize in advance if this is the wrong section, it seemed the most appropriate Dolphins are able to produce rings of air which seem to counteract buoyancy by rotating ( I'm assuming rotation ) https://www.youtube.com/watch?v=bT-fctr32pE How and why is this true ? Thanks

If fan blades move in a circular way how is the air moving towards you (in front of fan) ? Also propeller and fan have different shapes, does it mean they work different?

Let's say that I have a stick with weight evenly distributed throughout. I attach a fan to one end of the stick, then balance it from its new centre of mass. I measure the distance from the ground to the stick then drop it. The stick tilts up towards the side generating more air resistance (fan...

Folks, I have an application that will require an air inlet port to occasionally be exposed to water (splashing mostly), a simple splash guard will likely not work. Are there any off-the-shelf or simple solutions that anyone can think of that can be used for keeping the water from entering...

Homework Statement A puck of mass m is kicked up an incline (angle θ) with initial speed vo. Friction is not present, but air resistance has a magnitude of f(v) = cv2. Solve Newtons second law for the pucks velocity as a function of t on the upward journey. How long does the journey last...

I had an idea for a type of shoe similar yet different from air Nike, and I would appreciate some comments. A hind foot air chamber would be compressed upon a runners foot strike ( with a force up to three times body weight). The air would be pushed through a one way valve into a rigid mid...

I am designing an almond dehydrator as a part of my university project and need some advice regarding air flow in the dehydrator. There is a hollow perforated cylinder with a heating device in the middle. This cylinder is divided into two sections. The lower section has to take in cool air...

Homework Statement A hair dryer is basically a duct in which a few layers of electric resistors are placed. A small fan pulls the air in and forces it to flow over the resistors where it is heated. Air enters a 900-W hair dryer at 100 kPa and 25° C, and leaves at 50° C. The cross-sectional area...

Homework Statement please refer to the question, since at the positon Q , the lighr ray is blocked by the substance , (as in the diagram) , why the bright fringe is seen at Q , In my opinion , it it should be a dark fringe. whereas at P , the lighr ray is not blocked , so it should be bright...