What is Altitude: Definition and 249 Discussions

Altitude or height (also sometimes known as depth) is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The exact definition and reference datum varies according to the context (e.g., aviation, geometry, geographical survey, sport, or atmospheric pressure). Although the term altitude is commonly used to mean the height above sea level of a location, in geography the term elevation is often preferred for this usage.
Vertical distance measurements in the "down" direction are commonly referred to as depth.

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  1. kvidtr

    Can Geiger Counter Ticks be converted into particle/wave counts?

    TL;DR Summary: Currently working on a project for lab where we're sending Geiger counters 100k feet into the air. Goal is to determine radiation as a function of altitude. Need some guidance. Hi everyone, I'm currently working on a project for lab where we're sending Geiger counters 100k feet...
  2. M

    I Effects of altitude on liquid CO2 utilization

    I’m a contractor using liquid CO2 (LCO2) to freeze water pipes (for valve maintenance) while the water service remains at full static pressure (i.e., water is not flowing). I do the work in two locations: (1) near Denver, CO, where the altitude is 5,300 feet and (2) near Detroit, MI where the...
  3. eneacasucci

    I Variation of air temperature with altitude

    Considering the approximation of perfect gas, I don't understand why at higher altitude the temperature is lower. Intuitively it is clear to me, but I do not understand the kind of transformation that takes place; the gas is free to expand and the pressure too is not constant, since it decreases...
  4. A

    High Altitude Platform: Power Requirements

    How would I approach this task: I have a platform 10x10 meters footprint, 15 meters height, I need it to permanently float at about 10km, doesn't need to navigate/steer. That volume can contain some tech inside like balloons, batteries, propellers, solar panels etc. What is the power requirement...
  5. Ben_the_Druid

    I Vacuum pump operating at high altitude

    Hi I live in a high Altitude around 2500 meter over sealevel. I have a vacuum pump, at max my vacuum meter shows 21 inHG inside the vacuum chamber . my vacuum pump(welch 2014B) has a max of 40 torr it say the technical datasheet. What is now my endpressure in torr in my vacuumchamber?It's...
  6. B

    B Distance between two points on Earth doesn't increase with altitude?

    Consider the following example: Point A has coordinates 45 lat, 0 long. Point B has coordinates 45 lat, 2 long. Both points are 5000 ft above sea level. The distance between them is X. Point C has coordinates 45 lat, 100 long. Point D has coordinates 45 lat, 102 long. Both points are at sea...
  7. M

    Does climate change affect air density at altitude (scale height)?

    Increases in global temperature change affect the tree line and presumably comfortable habitability via temperature, and average air pressure associated with weather patterns. That's not what I mean. I'm thinking a 1/50 increase in kelvin temperature might increase the scale height of Earth's...
  8. M

    I Unbalanced forces acting on a ball at maximum altitude

    When a ball projected vertically upright reaches its maximum height is it instantaneously stationery (calculus provides for instantaneous events) before it starts its downwards journey? is gravity acting on the object at that instant? Newton provides that an object at rest must be subject to...
  9. A

    Unbalanced force to find altitude of airplane

    Since the airplane is flying at a constant speed, then the lift force equals the weight of the airplane. This means that the lift force prior to acceleration is the mass * gravity constant = 29400 N. When the airplane increases horizontal speed, the lift force increases to 30 kN. This means...
  10. S

    I Confused about declination, elevation & altitude

    They seem to be similar terms, although elevation & altitude seem to be the exact same thing. AIUI, the declination of astronomical object refers to the latitude on Earth where it is at the celestial zenith - i.e., straight up, along the line from the Earth's center and surface at such zenith...
  11. J

    MHB Bird Flying Speed at 10m Altitude

    A bird is flying at an altitude of 10m above you, his angular position from your point of view is changing at 0.5 rad · s^-1. How fast is the bird flying when he is directly above you?
  12. duchuy

    Altitude of Geostationary Orbit

    Hi, They gave me this formula T = 2piR / v, with T the revolution period of the satellite, R the distance between the center of masses and v the velocity. They gave me the value of G and the eath's mass and asked to determine the value of R. I don't even see fromwhere I should start... Thank...
  13. K

    Atmospheric pressure as a function of altitude

    Summary:: i) Set up a differential equation that describes how the pressure ##p## varies with the distance r from the center of the planet. Hint: You can base your reasoning on static equilibrium and Archimedes' principle. ii)Calculate how the atmospheric pressure p and the density of the...
  14. E

    Find the altitude and the speed of two jets with Doppler Effect

    Being honest, I couldn't do any works for this problem... (even couldn't start...) Does anyone can help me for solving this...? Thank you!
  15. cwill53

    Calculating Pressure & Density Proportions with Changing Altitude & Temperature

    I got the correct answer to this question with the following calculations, but I do need some correction in terms of what units I'm integrating across. ρ##\rho ## is density. mtot=n##m_{tot}=nM##, where n is the number of moles of a substance and M is the molar mass of the substance...
  16. S

    Partial pressure of oxygen at a certain altitude

    The pressure of oxygen at sea level = ##\frac{20.9}{100} ~\text{x} ~(21.2 ~\text{x} ~ 10^3) = 4430.8~ \text{Pa}## Then I do not know how to calculate the pressure at altitude 7000 m. I tried using P = ρgh (taking ρ as density of air = 1.3 kg/m3) then subtract the result from 4430.8 Pa but got...
  17. Anand Sivaram

    I Viewing Planets or stars from a high altitude

    We can not see planets or stars during the day time because of the scattering of the sunlight. But, in space, all planets and stars would be visible. Consider the situation that a rocket is going to space during the day time. At what altitude these stars or planets would become visible? On...
  18. T

    What outer structural materials are suitable for high altitude?

    Homework Statement:: n/a Homework Equations:: n/a Hello , I am researching some material science and looking for suitable structural materials for high altitude , low level orbit flight . Would a carbon structure be suitable or would there be pressure problems that cause structural collapse ?
  19. H

    Magnetism vs Altitude: Magnetic Pull & Gravity

    Magnetism as an attractive force can overcome gravity and lift things. I'm suggesting that a horseshoe magnet will overcome gravity and lift things off of the ground. Is there a reduction of magnetic pull with altitude?
  20. S

    Why rocket altitude does not increase proportionally?

    I thought it is because of the consevation of the energy, so I used (gravitational potential energy at the top = elastic potential energy). Since the mass of the rocket never changes, I supposed mass= 1kg, and k value is unknown. As a result, I got the result that k value is decreasing as...
  21. russ_watters

    Hypoxia: Altitude vs Displacement

    I work in HVAC, for those who don't know, and one of the things that you need to protect against in labs and chiller rooms is the risk of asphyxiation due to oxygen displacement by an inert gas. This is often described as analogous to high altitude hypoxia - and the math is related - but is it...
  22. E

    Altitude - Why is it a Scalar?

    Homework Statement How come altitude of a mountain is a scalar? Homework Equations Scalars = only magnitude Vectors = have magnitude & direction The Attempt at a Solution - Doesn't altitude of a mountain have both magnitude and direction (direction being measured straight up 90 degrees to the...
  23. N

    B Skydiving from Space -- maximum altitude?

    Hi everyone. I'm a skydiver. i would like to know the maximum altitude from where i can jump from the space and to be able to free fall back to Earth without geting lost in space. i think the actual record is 41425m. here is a brief story about world record spacedive...
  24. B

    I Atmospheric Lapse Rate (calculating the altitude of cloud formation)

    This is probably more of a p-chem question but I figure you guys are smart enough to answer this. FREEZING LEVEL CALCULATION: Per FAA "A standard temperature lapse rate is when the temperature decreases at the rate of approximately 3.5 °F or 2 °C per thousand feet up to 36,000 feet" Easy...
  25. Benjamin Fogiel

    A rocket burns out at an altitude h above the Earth's surface

    Homework Statement A rocket burns out at an altitude h above the Earth's surface. Its speed v0 at burnout exceeds the escape speed vesc appropriate to the burnout altitude. Show that the speed v of the rocket very far from the Earth is given by v=(v02-v2esc)1/2 Homework Equations KEf-KEi=Ui-Uf...
  26. AntSC

    Modifying Newton's Kinematic Equations for High Altitude

    I recently watched a video on youtube where a guy fires a 50 cal. rifle straight up into the air and measures the time of flight at about 100s. It got me thinking about what altitude the round reached. So I used the kinematics equations and obtained a value of 12.25km. Amazing, but I wondered...
  27. T

    Can an iPad battery be affected by altitude?

    Specifically, I'm referring to the cabin of an airliner being pressurized to about 8,000 mean sea level. Technically, the air is less dense, and I've wondered if there is a cooling issue inside the pad's board that results in a less efficient operation? I fly regularly, and I can take a fully...
  28. J

    B Lowest possible altitude for a Satellite

    What is the lowest altitude for a satellite to orbit?
  29. Kelly Andrew

    Why would a petrol engine stall at an altitude?

    The engine was used to propel a small home made air craft. It worked very well while it taxied away and went airborne, then at a certain altitude it stopped abruptly then came crashing down. Why? And what simple engine design can sustain the air craft?
  30. GilGiy

    B Airplanes Landing & Altitude Problem

    First I'm going to say that I was supposed to select a prefix for this thread... I'm not sure what that's for so my apologies if I did it wrong. So here's a problem that I was presented with a bit ago (by a flat earther[emoji849][emoji19][emoji44]) and I'm sort of confused. It's been about a...
  31. Laurie K

    A Calculating the Altitude of a Nominal Burst

    Does anybody know how to calculate an incoming satellites Altitude of Nominal Burst (not balloon burst altitude) from solar X-ray flux and particle precipitation rates along with other standard variables? For reference the following link is to an Australian BOM Satellite Orbital Decay...
  32. N

    Venus' temperature, radiation values and altitude

    Hi, I have a list of measured temperature values of Venus at altitudes from several missions to the planet. This temperature is a combination of outgoing thermal emission from the planet, incoming thermal emission from the sun and any chemical reactions going on in the atmosphere. Can I use...
  33. MattRob

    Flight Mechanics - Maximum Cruise Altitude

    So, I was helping someone with some science fiction stuff and got to poking into flight mechanics. So we've got a balance of lift and weight, and drag and thrust. The speed at which thrust and drag cancel determines the speed of flight. The speed of flight determines lift, and lift must cancel...
  34. S

    Launching a rocket from high altitude

    I have a project where I will be launching a rocket from a high altitude weather balloon. I am planning on launching the rocket at around 70Km or even higher. My main concern is the igniter not being able to ignite the engine because of the low amount of oxygen. Is there any way around this...
  35. oobgular

    Change in humidity with altitude

    Homework Statement So I sent a humidity sensor up in a weather balloon, which gave a reading for relative humidity. I eventually want an absolute humidity, but I am unsure whether I need to correct the output based on the changing density and atmospheric pressure with altitude. Homework...
  36. Cheesycheese213

    Does temperature change with depth in a fluid?

    Hi, so someone probably has already asked this, but does temperature increase or decrease with depth in a fluid? I thought it would decrease since it has more pressure but it is probably wrong, or doesn't make sense. I was confused because the ocean gets colder the deeper you go, but then does...
  37. oobgular

    Far IR light intensity as a function of altitude

    Homework Statement Hello, so I'm in a class that is building sensors and sending them up in a weather balloon. For my project, I am wanting to quantify the greenhouse effect by measuring the intensity of infrared light emitted as thermal radiation from the Earth as a function of height-- the...
  38. Blank_Stare

    Does electricty gain / lose power traveling up / down hill? [Not]

    (I Live in Michigan - no power at home since yesterday, and likely not until Sunday - 4 days, because of high winds.) My software genius boss (really, he's very smart,) is trying to tell me that the reason that the power companies do not bury power lines, is because it costs money to push it...
  39. A

    B Dynamic Fluid (airplane landing/decrease altitude)

    Hi guys.. I've some discussion with my friend. We are teacher. So we must carefully to answer question for student.. there the question is From figure below, p2 and p1 applied on plane's wings. When airplane landing/decrease altitude, which condition must occupied A. P1=P2 and v1=v2 B. P1<P2...
  40. J

    Max altitude of a model rocket

    Homework Statement Hello all, I have to determine the maximum height of a model rocket. The rocket is launched at an 45 degree angle The finale velocity is 15,69 m/s (v) the extutevelocety is 14,23 m/s (c) The total mass is 180 gram (m) or m0) The emty mass is 52 grams (mf) The mass pr sek is...
  41. Daquicker

    Minimal altitude to start a “Suicide Burn” - variable thrust

    Homework Statement I'm trying to calculate the absolute lowest safe altitude above a planet's surface to start firing the thrusters on a simulated lander in order tot just reach vCraft = 0 at the planet's surface. The force the craft's thrusters responsible for desceleration generate is...
  42. S

    Measuring Altitudes in Aircraft: What Instrument is Used?

    Which instrument is used to measure altitudes in aircraft's
  43. L

    Operating a portable ultrasound machine in -30 degrees C

    Dear friends. I am a cardiovascular health researcher writing on behalf of my research team based in Copenhagen, Denmark. We plan to conduct a high-altitude field study on cardiopulmonary function assesed by ultrasound on Aconcagua summit in near 7000 meters altitude. Reports say it will be...
  44. Oannes

    Finding Altitude When Given g = g0(Re/Re+A)^2

    Homework Statement [/B] g = g0(Re/(Re + A))2 g is the acceleration due to gravity. g0 is the acceleration of gravity at the surface of the earth, A is altitude, and Re is the radius, approximately 6380 km. Assume g0 = 9.8 meters per second squared. If the value of g is 9 meters per second...
  45. M

    MHB Right triangle, feet of altitude, angle bisector and median

    Let $\triangle ABC$ be a right-angled triangle with $\angle A = 90^{\circ}$, and $AB < AC$. Let points $D, E, F$ be located on side $BC$ such that $AD$ is the altitude, $AE$ is the internal angle bisector, and $AF$ is the median. Prove that $3AD + AF > 4AE$ My solution. Can you check it is...
  46. Z

    Portion of Altitude of a Triangle Inscribed in a Circle

    Homework Statement In the figure Q image2.jpeg (attached), equilateral triangle ABC is inscribed in circle O, whose radius is 4. Altitude BD is extended until it intersects the circle at E. What is the length of DE? Solution figure is attached. They formed a right angled triangle & calling it...
  47. Alfreds9

    B Visual proof of being at altitude?

    Hi, this may seem like an odd questions to most of you but I'd still like to ask what could be some visual proofs of being at high altitude, say 10,000 feet above sea level. While any said proof is not extremely rigorous or untamperable and probably little more than a showy capture to add to...
  48. Alfreds9

    Calculating air pressure from altitude, RH and temperature?

    Homework Statement [/B] This is a practical problem, no homework question. I'd like to determine pressure (and O2 partial pressure) at altitude, yet following a more realistic real-world calc including measured data like relative humidity (RH) and temperature at that altitude, yet all I can...