A flying saucer (also referred to as "a flying disc") is a descriptive term for a supposed type of flying craft having a disc or saucer-shaped body, commonly used generically to refer to an anomalous flying object. The term was coined in 1947 but has generally been supplanted since 1952 by the United States Air Force term unidentified flying objects (or UFOs for short). Early reported sightings of unknown "flying saucers" usually described them as silver or metallic, sometimes reported as covered with navigation lights or surrounded with a glowing light, hovering or moving rapidly, either alone or in tight formations with other similar craft, and exhibiting high maneuverability.
MENTOR Note: Post moved from General Discussion to Aerospace Engineering
How did you find PF?: I found PF because of a late night idea I had when I was bored, but I have no idea how to do it so I was looking up information when I came across this app.
I'm sure most of you guys on here know...
I haven't played many video games beyond the early Pong games in undergrad and some Flight Simulators after I graduated. But my kids and grandkids are definitely part of the video game generation, and after watching some of those games and some advertisements today on TV that had the players...
Please see below question and formula for Z(t) - position,
I differentiate twice to get the below formula for acceleration.
But I cannot solve it because of the unknown t...
What is t representing in the original equation?
There once was a thread, a short thread, about a flying car.
https://www.physicsforums.com/threads/flying-car.413351/
Move forward 11 years, and a Flying car completes test flight between airports
https://www.bbc.com/news/technology-57651843
I wonder if they've tested in down draft, or...
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?
I am trying to understand how birds fly. If you consider a plane, using it's engine & streamline shape of the wings, it can create a low pressure region above the wings and high pressure region below and this makes it fly and the upward force is proportional to the speed.
Birds seem to flap its...
I found it confusing since there is only "mutual" speed of both aircrafts and hence I do not know how to correctly put it into the common Dopplers formula...
My solutions (attempts) :
a> w=v/r | r=6.35x10^6m | therefore V=7.04x10^-5 m/s
b> speed of rotation is faster at the equator than the pole as w=v/r. As w remains constant, as r increases towards the pole V has to decrease.
c> F = W - R
d> Stuck here. I presume that I have to use the equation...
This video has been popping up in my feeds over the last day or so, as I'm sure others here have also seen it by now. Looks like it has been taken with one of these super zoom cameras.
After watching it carefully several times, it doesn't appear to be done with creative video editing, which I...
The given solution is:
However, I could not agree this solution, and my solotion is:
So which one is correct? it seems a exponential decay would be more convincing.
Thanks!
So, some days ago I was rethinking my childhood and remember that I was obsessed with ben 10, particularly with the hoverboard in the film (https://ben10.fandom.com/wiki/Hoverboards). Right now, I really want to construct a replication of it, but I am stuck with some problems. First, what type...
I am not sure if I am in the right place... I am, I guess for all intent and propose, a "dream" guy. I come up with something and cannot get it out of my head until I have explored all the possibilities. About 7 years ago, I came up with a thought about a "flying vehicle", Prop driven without...
Hello! This is my first post here, and I look forward to many more! This is a sort of riddle I was told today, and left me full of doubts.
So, the 'puzzle' was the following:
" There's a man carrying behind his truck an enclosed trailer full of birds inside it. All the birds are standing on...
Some spiders are known to fly on the breezes by extruding silk strands (like web material) from their abdomen. This is commonly thought to be caught in the wind and carry them away. This would explain the occasional spider you might see drifting by when you are outside.
Many (including that...
Homework Statement
Consider a platform (mass: M) which horizontal surface AB s smoothly joined to vertical surface CD as shown in the figure below. Initially, the platform is fixed in place on a horizontal floor. A small object (mass: m) is placed on AB and given an initial speed of v in the...
Hi,
Reading about different ways to lift a human being, I've come to realize the easiest is simply manipulating density as follows:
Denisty of Air at STP: 1.20 kg/m^3
Density of He at STP: 0.000179 kg/m^3
Therefore for every cubic metre (m^3) of air displacement, lift achieved is ~1.2 kg/m^3...
My mom lives across the country from me and fosters dogs that need a home. Her recent foster is a St Bernard that was given up by a family because the dog was getting too big (not sure what they expected from a St Bernard). The dog is in good hands now but I was considering paying to fly the dog...
Homework Statement
A bird can fly in still air at 100km/h. The wind blows at 90km/h from W(x degrees)S. The bird wishes to return to its nest which is due E of its present position. In which direction, relative to the air, should it fly?My textbook says that the velocity of the bird relative to...
I recently watched a rerun of "Jurassic World" on TV. Seeing the pterodactyl attack, I got to thinking;
Is there a formula to determine the maximum weight a flying bird, bat, pterodactyl, or whatever can have given the force of gravity g at the planet's surface, and the atmospheric pressure?
Homework Statement
A plane is taking off from an airport directly west of the airport it wishes to touch down in. The plane in still air can travel with a constant speed of 730 km/h. If a wind is blowing constantly at 92 km/h [45° S of E], at what angle must the plane fly to compensate for the...
Quetzalcoatlus is a prehisotric bird that can weigh up to 500 pounds. I am so shocked how a bird weighing up to 500 pounds can fly. How is this possible? Wouldn't the bird be to heavy to fly? Does the bird defy the laws of physics?
1. A plane is flying at 80m/s [n] in level flight. Draw a freebody diagram and state whether forces are balanced or unbalanced.
-i wasn't sure what to draw :/
Why are there no flying snakes or flying scorpions with venoms?
And if some dinosaurs can fly.. why can't something lighter like humanoids also fly? In this age where traffic is at stand still.. don't you wish you can just sprout you wings and fly in the cities?
Any studies what kinds of...
Question: Starting from rest, the toy plane flies around a circle of radius 2m, three times in 3 seconds. There is constant tangential acceleration, fins the magnitude of the acceleration at the end of 0.5s.
My solution (most likely wrong):
Circumference= 2pir= 4pi= 12.56631
Distance...
So, I was thinking today about Newton's Law Of Universal Gravitation. Well, when I was thinking, I remembered that if you were to drop a rock, the Earth would be pulled the slightest bit. Right? Anyways, if that’s the case, then if there are enough birds and planes flying around in the sky, then...
Recently the Bugatti Chiron set a record of some sort for rapidly accelerating to 249 mph and then dropping back down. The engine is something to the effect of 1500 horsepower and the vehicle isn't terribly heavy. Old Airplanes had engines below 400 horsepower and ultra lights can be far less...
Homework Statement
A pilot flies a plane from A to B, 400 miles due North of A. If a Westward wind of ##20 mph## is present, determine the direction the pilot needs to aim the plane relative to the air and the speed at which he needs to fly the plane in order to arrive at B in two hours...
Homework Statement
A jet fighter flies in a vertical circle of diameter 1000 m. The speed of the aeroplane at the bottom of this circle is 185 m s-1. For the aeroplane at this point, calculate:
Apparent weight
Homework Equations
Fc = mv^2/r
Ac = v^2/r
Fn = Fg + Fc
The Attempt at a Solution...
In the eponymous short story Lunarians have a large dome they can use to fly under their own power, using wings they rent.
BUT, let's posit a person who regularly runs 26.2 marathons on Earth. Is this person fit/strong enough to actually fly in that arena? SWAGs accepted.
Homework Statement
A bullet flying horizontally hits a wooden block that is initially at rest on a frictionless, horizontal surface. The bullet gets stuck in the block, and the bullet-block system has a final speed of V_f. Find the final speed of the bullet-block system in terms of the mass of...
Homework Statement
helicopter is flying in air it goes A,B,C,D points
which are distributed in square
and helicopter goes one circle in 4 hours
if wind is blowing in direction from A to D
then the whole circle is flown in 3 hours
question: how does it takes to fly from A to C if wind blows in...
Homework Statement
The flying disc except rotation moves up and down. Show that such movement will be suppressed by frictional force of air, which has a force momentum relative to the center of disc ##N=-K\omega##. What is the time profile of this process?
Homework Equations
##L= T - V##...
Homework Statement
A bullet flies with initial speed v0=200m/S under the angle pi/3rad. Find the maximal distance of flying
Homework Equations
L=v0^2*sin2a/g
The Attempt at a Solution
L=40000*sqrt(3)/2/10=3464.1 m
OK I'm not sure if I put this in right subforum.
I remember once reading in some science book by Isaac Asimov that the heaviest any flying animal can be is 22 kg, but I read on Wikipedia that Quetzalcoatlus may weighted up to 250 kg. So how come there's such a great difference in that...
Hi,
I was wondering if someone could please help me to understand :
1) How can I prove that a Pendulum is following SHM?
2) Also, does being isochronous also mean that the pendulum is following SHM?
Thank You very much.
What would happen if an aircraft was fast enough to match the speed of the rotation of the Earth and it decided to fly against it matching that exact speed (earth's rotation)?
I would imagine it would look like Earth was speeding up but would there be any other physical effects on the aircraft...
Homework Statement
Bindi pops the cork off a bottle of champagne. The cork travels vertically into the air. She notices that the cork takes 4s to return to starting position.
a) how long does cork take to reach maximum height?
Homework Equations
I know that a= -9.81m/s/s, and the final...
so the question has been previously answered as to what would happen if a fan was in the vacuum of space. but the responses I seen all ask what the fan would push on or up against. what if the fan where to push against light? solar sails are able to have a force push against them in space?
Usually when we calculate the kinetic energy acquired by a positive charge as it moves in the direction of the electric field produced by another positive charge, we assume that the source charge remains stationary and so the loss in potential energy for the moving charge is equal to its gain in...
Given a scenario, where a car is going at a speed of 150 km/hr on a straight and level road. There is an insect flying inside the car. To a person inside the car, (I really do not know how to say this, but I hope you understand), the insect is flying naturally, basically, the speed of the car...
Great youtube introduction video about Quantum Field Theory (QFT) from a couple of days ago by Dr Don Lincoln @fermilab. The video and description of a particle being a disturbance in a field and flying through the air at 3:25 is especially compelling.
Homework Statement
A bird flew along a helical path r(t)=<5cost,5sint,2t>, at time t=10 second, the bird died instantly. where did it hit the xy-plane ? g=32 ft/s/s.
Homework Equations
r(t)=(v_0 \cos\theta t) i+(v_0 \sin\theta t - 0.5gt^2 + h_0) j
The Attempt at a Solution
taking derivative...
If two guys, each sitting on a different Earth-like habitable planet, fly in the opposite directions, each at the speed of light, which guy would age slower? And slower compared to what?
My own understanding is that they both age normally. Because Special Relativity doesn't describe...
My idea for a flying car...The image below shows my idea for what i call a flyer [flying car/vehicle]. The basic principle is to utilise lift instead of thrust momentum as the means of take-off and flight. This means it won't blow air everywhere and doesn't have dangerous blades [also has safety...
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Hello.
When people started flying it was quite bumpy because of turbulence below 10000 meter.
So todays air travel is mostly above 10000 meter to avoid a bumping turbulent ride.
To develop a future flying car this must be dealt with because people don't want to be thrown around in the...