Engineering

All cornering wheels slide because they are changing their rolling direction, but, the phenomenon of slip angle only occurs when the tread does not slide. This sliding fact is proven by simply studying the travel of a wheel through a turn and noting the vertical axis rotation of the wheel as it proceeds. No matter how flexible the rubber on a tire, the tire has to slide to change direction and follow the curved path. Slip Angle is tied to the belief that the tire tread is laid on to the road and stays in place on the road until it reaches the rear of the contact patch. Slip angle phenomena such as relaxation length, pneumatic trail and self-aligning torque are all de…

Firstly I will apologies if this is in the wrong place, the question I have falls under thermodynamics (maybe) but I'm working on an engineering project. Is there a way to determine the time it would take to boil an amount of water when you only have a temperature? I know you can calculate it if you know the kW/h or BTU used for heating however I do not, I only know the temperature. Let me explain a little better: Lets say you have a metal pipe that constantly has gas flowing through it at 400°C. If this pipe were to go through a tank of water how would you calculate firstly whether you could boil the water, and secondly how long it would take? Basicall…

I have come up with an idea for a solar car. Now I am not going to build it because it would require welding and although my dad knows how to use a welder and a plasma cutter, I still think it would be too dangerous for even my dad to build, not to mention expensive. Even if he cut all the metal himself, the metal would be expensive. Not to mention it could start a fire which would mean no more solar car. But just because me and my dad can't build it doesn't mean I can't come up with an idea for it. So here is my idea. I was thinking that maybe voltage could determine velocity. When the car is charging, it is connected to a solar panel via a cord which plugs into th…

I was wondering how difficult it would be to use lasers to propel a light sail (let's say 500m x 500m) to 12% of the speed of light. The payload would be 5 megagrams. Without a way to slow it down, it would fly through the destination star system too quickly. I thought about crashing the payload into something but with that much kinetic energy, it's like a nuke going off. My payload probably wouldn't survive. I was thinking, what if you have two light sails and when you near your destination, you release the second light sail and the laser array back home bounces the lasers off the front light sail. The front light sail would be speeding up with the back light sail (…

Hello,I would like to calculate the difference between a white surface wall surface and the same kind of wall but with brown outer surface. I would like to know the reflection and absorption indices and then calculate the surface temperature of the wall in the two solutions at the same temperature as the outside air temperature. How could I proceed?Thank you in advance.

We are looking to open a golfing driving range whereby you hit the golf balls at targets and if they go in one of the holes, you are awarded a different number of points. This is already being done by a company with Radio Frequency chipped balls and is patented. I wonder if there are any other types of sensor that might work like laser/infrared?? Really appreciate everyones help! (also I was unsure if this is Physics or Engineering so I double posted, sorry!)

As mentioned before, I am working on a sci-fi project and in my fictional world the earth is being hit by repeated EMP’s, one every few hours. But these are not EMP attacks—they aren’t designed to target electronics by covering a wide range of frequencies, they are like solar flares and just cover a lower set of EMP frequencies. I am trying to design how the world will have changed to live under these conditions. As an example, electric and communication lines will have moved underground, with communication access points poking above ground here-and-there. They are covered in Faraday cages that block low-frequency pulses but allow high-frequency signals through, …

I have no MSc and PhD degree but I am writing academic and engineering projects. how can we sell our projects?

I want to make a kind of pergola with a tiled roof on one side of the house, 6 m along the side of the house and 3 m wide. Usually, these pergolas have supporting posts every 3 metres, but I particularly want a span of 6m between the corner posts, which means I need a strong supporting beam to hold up the roof. A builder friend suggested that I get two 6m laminated wooden beams of cross section 100x200 mm and sandwich a metal sheet (thickness 3 - 6 mm) between them, bolting the three together along the length of the beam. This metal sheet would be vertical, thus effectively working as an I-shaped RSJ, but the whole thing would be much more attractive than just an RSJ. …

I was thinking about my aliens and their generation ship. I did a lot of research on light in general as well as sunlight in particular. Since the aliens are moving away from the sun and facing away from the sun and towards the outer planets when they start their trip with the humans in space, that already dramatically decreases the amount of sunlight that reaches them. But that intensity goes down with the square of the distance. So if you go twice as far from the light source the light source will be 4 times dimmer and if you go 3 times as far the light source will be 9 times dimmer, etc. It eventually gets to a point where it is not visible anymore because only individ…

Hello, stone collectors and everyone! Moon rocks help understand our world, but all we have are meteoroids and 382kg of samples quickly collected from 6 small sites by the Apollo missions http://en.wikipedia.org/wiki/Moon_rock so a mission to bring back Moon samples from new sites would be exciting. I propose here a script to prospect many sites - including at Moon's far side :good: - taking the time needed to explore larger areas and pick the best samples. We don't need six Saturn-V for that goal because robots exist now and my sunheat rocket engine changes the game http://www.scienceforums.net/topic/76627-solar-thermal-rocket/ so one middleweight launch suffices. --…

Superb craftsmanship worth sharing. Enjoy : ---->

This is a sister to my first topic: http://www.scienceforums.net/topic/108036-moon-explosion-and-radiation-for-sci-fi-book/ In my story, a major explosion sets humanity back in technology, and there is a major explosion on the moon. It could be the moon explosion that generated an EMP, or it could be a major solar flare that generated the EMP on earth and also caused the moon explosion. I'd prefer to have it all caused by the moon explosion (NEMP). If the explosion has to be nuclear, that fits my current idea as to why it happened at all. But here I want to ask another question. For my story it is important that the EMP bursts continue several times each da…

working-in the normal state(no cracks) no emf is induced in secondary coil.when crack is there the magnetic flux changes hence emf is induced in the secondary which turns on the thyristor and hence buzzer.will this circuit work as intended

I saw a youtube video of RC planes. What if engineers would invent RC real airplanes for transportation? What is your view in this suggestion?

I'm not entirely sure where this should go but this seems like the right place. I've been watching a bunch of hoverboard videos lately. I mean the Hendo and the Lexus ones that really hover on electromagnetism. I know these need to hover over a special surface like copper to make the magnetic wave repel and lift, what I don't understand is what happens if you attach the metal surface to the hover engine device. Like something as simple as taking a thin sheet of the metal, hooking it on a cord tied to the hover device, and then let the hover device repel against the metal or simply being in a box with one end the magnet and the other the opposing surface. Does the ma…

The ISS cost a lot of money, I've seen estimates as low as 100 billion and as high as 400 billion. I've also seen arguments that it wasn't really worth it. I was just wondering why we didn't spend that money on a Star Tram. Right now, current rockets cost about $18000 per kilogram of payload. Space X, with their reusable first stage rockets, could bring that down to as low as $1200 per kilogram. I also learned about the Star Tram and on their site they claim that it could bring the cost down to $40 per kilogram. The site claims that the Star Tram can be built with known technology and materials unlike the Space Elevator. The Space Elevator gets so much attention even …

Any thoughts on the feasibility of using a sail kept aloft by balloons rather than a traditional mast?

So, I was on the website known as 4chan, lurking at some posts on /sci/ (the board is called "science" just in case ya'll don't know.) and trying to find something interesting. When I suddenly found myself looking at this picture of how telomeres work and why they're the reason we age. So i ended up asking myself... how do we slow or stop telomeres from shortening? Here's the post if ya'll want to see (hope it didn't 404 by the time you see it -.-): http://boards.4chan.org/sci/thread/9069182 So, I found myself searching how to do what I'm asking when I come across a study from Harvard. Here it is if you want to see it: http://newatlas.com/telomerase-aging-h…

I was thinking about all the excretions and body fluids that end up in sewage and thought "Bacteria and oxygen might do it for less cost but it is less efficient than my method" So here is what I was thinking. At some point in the pipes there is a poop catcher and right next to it a valve that will only open when there is no fluid. This diverts the poop to a different set of pipes that eventually leads to making a human poop biosolid. Meanwhile, the rest of the fluid continues on through a series of 7 filters each designed to catch something you don't want in the water and is microscopic. The first filter blocks cells(so blood cells, bacteria, fungi, protozoa, endot…

Hello, I'm a person who is in her mid teens and wants to understand and make it possible for human kind to fly. Im fully aware of lots of problems with this like how would we connect our nervous system to the wings, would the brain even intake it? And our body mass is much too large I'm very aware on that I also know most people have tried very hard to make it happen I'm simply one who shall carry on that legacy and hope to makeep it happen (:

So my friend and I were walking in the rain yesterday. And obviously we had our phones drenched. Mine worked fine but hers didn't. After a while when we went back home and her phone started to work again, she told me that she had kept it in a rice container for a while and it started to work again.Now she may be lying and I'm aware of the water absorption capacity of rice, but does this even work like this? Is this some life hack we're all supposed to know?

HELLO EVERYONE, HEREBY I ENCLOSED THE PICTURE OF THE BLOCK. I WANT TO FIND THE DEFLECTION ON BLOCK AT 35mm FROM GROUND DUE TO 2x M12 SCREWS WITH TORQUE 120Nm. I FOUND PRACTICAL DEFORMATION AS 0.011mm. BUT I COULD NOT GET THE THEORETICAL SOLUTION FOR THIS PROBLEM. PLEASE ANYONE HELP ME TO GET THEORETICAL DEFORMATION. THANK YOU, REGARDS VARATHA

In analyzing the discussions on coin tosses we have going, I came across a question that might have derailed the other threads, so I'll open it here. Persi Diaconis had Harvard engineers build him a coin-flipping machine for a series of studies. Apparently the device could be adjusted to flip either heads or tails repeatedly. I assumed the next natural test would be to see if the machine could be calibrated to flip a coin on its edge every time, but I couldn't find anything on that. How easily/cheaply could a device be made that flips a coin onto its edge (virtually) every time?

High my name is Donar Craigie on YouTube I have a detailed description. You are correct more torque is needed to create speed, but I have done an experiment to show that constant torque can increase in speed against the same wind pressure. It is the principle of moments the torque is held constant on one side by increasing the distance [that is the blade side you would say] while the load is increased on the other side of the pivot without increasing distance, so the torque increases to compensate for the increase in speed on the blade side. For instance the pivot is at 50cm, the load is at 0cm and for the first trial a large light plastic plate is at 75cm which is 25cm f…