Altitude Definition and 250 Threads

Variations in Refractive Index of atmosphere with altitude ?? The queries i have are related to refraction of light. 1. How does the refractive index of air vary with the altitude ? If possible explain the reason for change. 2. Does the amplitude of a wave change during refraction?

The Problem: Why is it that r = rrE + h? r = distance from Earth's centre to satellite rrE = Earth's radius h = altitude Why is it that you find altitude by subtracting Earth's radius from radius? How does that make sense..

Hello my question is this: If we throw 2 objects which are same but their masses are different from the same altitude they drop to the land in the same time? (We consider that the friction force is active it's not negligible

I recently read that the STS orbiters have up to 300 m/s of delta-V available considering the weight of the orbiter and the quantity of propellant in the OMS. I also recall that leaving orbit requires some 100-150 m/s of delta-V depending on altitude. If deorbiting takes 100-150 m/s, then is...

Homework Statement Consider a horizontal slab of air whose thickness (height) is dz. If this slab is at rest, the pressure holding it up from below must balance both the pressure from above and the weight of the slab. Use this fact to find an expression for dP/dz, the variation of pressure...

Homework Statement A polaris missile has a mass of 1.4 x 10^4 kg and its engine has a thrust of 2 x 10^5 N. If its engines fire in the vertical direction for 1 min starting from rest, to what vertical height would it rise in the absence of air resistance? Homework Equations F=ma W=mg...

I have a (faulty!) cylinder filled with compressed air at 2,000 psi which leaks at a rate of 1litre/minute at sea level. What would be the expected rate of leak at an altitude of 8,000ft? thanks for your help.

If you are in the southern hemisphere in winter and the South Celestial Pole has an altitude of 20 degrees, what is your latitude on earth?

Homework Statement At the instant when theta is 120 degrees, the angle theta is increasing at the rate of 2.7 degrees per min. Find the altitude of the satellite and the rate at which the altitude is changing at this instant. Express the rate in units of mi/min. Homework Equations r =...

Homework Statement A rocket is launched at an angle of 53 above the horizontal with an initial speed of 100 m/s. It moves along its initial line of motion with an acceleration of 30 m/s^2 for 3 s. A this time its engines fail and the rocket proceeds to move as a free body. a. Find maximum...

Homework Statement A rocket is launched at an angle of 53 degrees above the horizontal with an intial speed of 100 m/s. It moves along its initial line of motion with an accel. of 30 m/s^2 for 3 s. At this time its engines fail and the rocket proceeds to move as a free body. Find the maximum...

Hypothesis A contained body of gas that is within a field of gravity will have differing temperature in differing locations within the body. These differing temperatures can be utilised to by a heat engine, to convert heat energy into other forms. Background Heat can be described as the...

I'm very unfamiliar with energy-use in aviation, but I am wondering about what effect altitude has on parameters such as gravity (i.e. weight of the aircraft) and air-density, which I would think affects friction and combustion as well as lift. One thought I've had is that higher velocities...

Homework Statement The missile has maximum horizontal range of 160km. What is the maximum altitude it can reach if launched vertically? Homework Equations v2=u2 +2as The Attempt at a Solution v=0 (because the velocity is zero when it is not rising anymore) u=0 a= -9.8 (up is the positive...

hye.. i'm working on my FYP project on designing and building a rocket controller which will react on altitude change thus shifting the angle of its fin to make sure the rocket fly to the right altitude. can anyone help me with the topic?

Homework Statement A helium meteorological balloon is made of a bag of impervious fabric that does not stretch, and when fully inflated forms a spherical shell of 1m diameter enclosing the He. At launch it is filled with He (at STP) to 15% capacity. The launch takes place in the Antarctic, in...

Homework Statement A 52 kg pole vaulter running at 10 m/s vaults over the bar. Her speed when she is above the bar is 1.3 m/s. Neglect air resistance, as well as any energy absorbed by the pole, and determine her altitude as she crosses the bar. Homework Equations 1/2mv2 = mgy + 1/2mv2...

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 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 =...

Hi I have a few question i don't understand how to complete. Homework Statement A model rocket leaves the ground, heading straight up at 49m/s. a)What is the maximum altitude?What are its speed and altitude at b)1s c)4s 2. Homework Equations ( For all questions) Constant acceleration...

Homework Statement A rocket is launched at an angle of 53 above the horizontal with an initial speed of 75 m/s. It moves for 25s along it's initial line of motion with an overall acceleration of 25 m/22. At this time its engines fail and the rocket proceeds to move as a freebody. a) What...

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...

The vertices of a triangle are A(4;2) ; B(11;6) ; C(-3;-1) What is the equation of the perpendicular bisector of side a? (i think -7x+14y=7) What is the equation of the altitude of side c? (i think -4x+7y=5) What is the intersection of the previous lines? i have no idea about this,please...

Hi, I was wondering if anyone here has any good suggestions for foam insulation for high altitude balloons. We're looking at temperatures as low as -60 deg. Any recommendations on supplier as well?

Homework Statement an egg boiled for 4 minutes at the top of a mountain does not harden Homework Equations The Attempt at a Solution pressure is lower at the top of a mountain than at sea level. Is the issue here the fact that pressure inside the egg does not build up sufficiently to...

Hello folks! I'm an arts instructor and painter and I intend to develop a series of works (not homework) based on the a troublesome issue (at least for me) that was out of our major in college and apparently no one I talked to had a solid answer for that. Considering that the horizon line is...

Homework Statement Which of these two triangles have a higher altitude (height)? NOTE: BOTH TRIANGLES ARE EQUILATERAL! Triangle 1 (all of the legnths going to the center are 665) Triangle 2 (lengths of each line going to center writen) Homework Equations none The Attempt...

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 =...

This is my first posting - I don't know whether its on the right section but I have a question is there a formula to work out how much thrust you need to get a certain weight of rocket up in the air, also for the rockets altitude? Thanks

Homework Statement The satellite S travels around the Earth in a circular path with a constant speed of 20 Mm/h. If the acceleration is 2.5m/s2, determine the altitude h. Assume the Earth's diameter to be 12 713 km. Homework Equations a_{n}= \frac{v^{2}}{\rho} The Attempt at a...

HI In Jet Engine, i want to know that the compressed air prssure changes before it enters into the combustion chamber from the compressor in various altitude and velocity or it is consatnt for altitude and velocity?

Homework Statement A 200kg weather rocket is loaded with 100kg of fuel and fired straight up. It accelerates upward at 35m/s^2 for 32 s, then runs out of fuel. Ignore any air resistance effects. What is the rocket's maximum altitude? How long is the rocket in the air? Homework...

[b]1. (a) Find the altitude above the Earth's surface where Earth's gravitational field strength would be four-fifths of its value at the surface. Assume re = 6.371*10^3 km. (b) Find the altitude above the Earth's surface where Earth's gravitational field strength would be one-fifth of its...

If you inflate an RV tire to 100 psi at sea level and then drive to 14,000 feet, discounting temperature, will the tire pressure be the same, lower or higher?

Suppose a company has developed a modification for almost all types of tanks such that when the tank is filled with an incoming fluid (which is at a certain pressure), it stores this pressure and uses it to take the fluid out of the tank with pressure, i.e even if the tank is at low altitude it...

A projectile is launched vertically from the surface of the Moon with an initial speed of 1210 m/s. At what altitude is the projectile's speed three-fourths its initial value? can someone please help me with this! i keep getting 1.96x10^5 m but it says that is not the correct answer thanks

I was just listening to New York ATC on 11.309 MHz. Al Italia flight 687 was asked to climb to flight level 360 but Al Italia said that they would be able to do that in an hour's time. A few minutes later the flight was contacted and they were asked to climb to flight level 360 by 01.15 GMT...

Homework Statement Could someone help me calculate the rate of expansion of gas (helium or hydrogen) in a balloon at different altitudes. temperature is -30f at all altitudes http://www.engineeringtoolbox.com/air-altitude-pressure-d_462.html <- chart for air pressure Homework...

how do you do heat energy questions? is it the energy lost? An unpowered 1600 kg object has an upward velocity of 7.0 x 10^3 m s at an altitude of 100 km above the earth. The object reaches a maximum altitude of 400 km. Earth 100 km 400 km v = 7.0 × 10^3 m s What is the heat energy...

Hello, This summer I would be interested in designing my own model rocket. I do not have a lot of aerospace/aerodynamics (read the NASA (http://www.grc.nasa.gov/WWW/k-12/airplane/)) knowledge but I do have a good grasp of math and physics. I would like to use a A or B model rocket engine and...

Homework Statement A remote-sensing satellite travels in a circular orbit at a constant speed of 8.2 x 10^3 m/s. Determing the altitude in kilometres of the satellite above Earth's surface. Homework Equations Fc = FG The Attempt at a Solution mv^2/r = GMm/r^2 v^2 = GM/r r =...

Homework Statement INTRO TO THE PROBLEM :For a circular orbit around a massive gravitating body, the speed depends on the radius according to the equation V = sqrt (GM/r) ; for elliptical orbits, the speed varies according to the equation v^2 = 2GM([ 1/r - 1/(2a), where r is the distance...

Homework Statement A child holding a helium filled balloon @ sea level (T= 20 C) let's go of the string. The balloon rises freely several thousand meters, where T = 5 C and P = 0.70 atm. Find the percentage change in the balloon's volume. Homework Equations PV = nRT percentage...

I am looking for some help and advice on the title topics. Looking at ideas for a final year project, and currently looking at doing a high altitude and long endurance UAV. My definition of high altitude is 100k - 200k. I have looked at some other uavs that have done this, including the...

Earth's atmosphere has roughly four molecules of nitrogen for every oxygen molecule at sea level; more precisely, the ratio is 78:21. Assuming a constant temperature at all altitudes (not really very accurate), what is the ratio at an altitude of 10km? Explain why your result is qualitative...

Homework Statement A 200 kg weather rocket is loaded with 100 kg of fuel and fired straight up. It accelerates upward at 33 m/s^2 for 34 s, then runs out of fuel. Ignroe any air resistance effects. A) what is the rocket's maximum altitude? B) how long is the rocket in the air? Homework...

Homework Statement Derive (from the equation of motion of a neutral gas and an assumption of constant gravitational field) an expression showing why the concentrations of neutral molecules decrease approximately exponentially with increasing altitude, and why the concentration of atomic oxygen...

How far above the surface of Earth would you weigh 69.7 percent of your surface weight? This is the work I've done but something isn't right and I'm not getting the right answer: 69.7(9.8)=6.67x10^-11(5.98x10^24)/r^2 = 683.06 = 3.98x10^14/r^2 r= 763329.61m (Incorrect) someone please...

Homework Statement An electric scooter has a battery capable of supplying 140 Wh of energy. If friction forces and other losses account for 60.0% of the energy usage, what altitude change can a rider achieve when driving in hilly terrain, if the rider and scooter have a combined weight of...

Homework Statement An electric scooter has a battery capable of supplying 120 Wh of energy. If friction forces and other losses acount for 60.0% of energy usage, what altitude change can a rider achieve when driving in hilly terrain, if the rider and scooter have a combined weight of 890N...