Drive Definition and 496 Threads

I have a completely speculative sci-fi question I've been wrestling with, and I'd love some feedback from better minds than my own: Lets assume we develop the technology to artificially generate gravity without mass (maybe using electrogravitics). We build a spaceship that can project a...

Can a variable frequency drive with the ability to control motor torque, be programmed to run at a certain speed and torque? Or can you only control one of these variables because a change in one will affect the change in another? I noticed that in certain drives, there is speed control and...

I've been having a problem lately with my computer. It's running 64-bit Windows 7, and has two external hard drives plugged in. Occasionally , I've noticed that sometimes when I attempt to do something in a program, even something as single as right-click on a cell in Excel, the computer will...

Alcubierre Warp Drive: Debate and Discussions (Force Fields; Dampners) I would like to first of all apologize if this is not in the correct location or if this thread violates any of the forum's rules. The purpose of this thread is to discuss, debate, and bounce ideas around regarding the...

Hi, I am facing some problem can i just downsize the motor that drive the fan as currently the fan is operated at full load but the flow rate is controlled by a damper. my thought is that is it possible to downsize the motor so it will operate at lower rpm therefore we no longer need to use...

You are wondering how fast you can drive your bike but not get your feet wet when the road is full of water? The answer is simple: about 2.5m/s (meters per second) or roughly 9km/h (kilometers per hour), or 5.6mph. See below for the demonstation: This is a simple physics problem which is...

Hi all, I am trying to build a circuit for driving multiple LEDs under test at a given current, and the LEDs are to be individually tested with multimeter. Now I know I could just run them all in series and they would get the same current, but if one LED breaks, then the whole circuit goes...

Is this possible? Inertial propulsion. If we take that nothing is faster than speed of light than we can take that reaction of force through matter can not be faster than c. If one body act on other body by force, than other body react with same amount of force to the first body...

Hi; I am new in this forum. I was looking for such forum and at last reached to the right one. A question is in my mind, if we drive the bike within 60km/h range, we achieve a good mileage but beyond this limit, mileage drops drastically while we cover the distance in short time as compare...

HiI would like to know, does the torque required to turn a pulley increases if you increase the tension? I have a system like this:pulley motor pulley car and a belt goes...

What is so good about having a hohlraum, and is it destroyed after every pulse?

Homework Statement In the badly loaded front-wheel-drive minibus shown in Figure Q26 the centre of gravity has been moved away from the driving wheels, determine the max acceleration possible in m/s2 if l=3.0 m, h=1 m, and the static co efficient of friction μs = 0.3. (Image is attached below)...

i was studying about four wheel drive/ all wheel drive and while studying about it i was just wondering how does your vehicle decide, to which wheel power should be transmitted more and to which one the power should be reduced, while cornering or while whee skidds.

This is a very blunt guess, but since light can warp space-time a bit better then gravity, and that light is a ripple in hyper space. Could it be possible for 14 powerful lasers that are guided by "mirrors" around the ship to form a circle powerful enough to reach warp speed? The idea of a big...

From what I can gather, the laws of physics are time sysmmetrical- the exception being the second law of thermodynamics. So could it be that our whole experience of time is driven souly by increasing entropy? Assuming that we live in a deterministic universe(controversial I know) all past...

Hi : lets examine the following scenario 1. M --------- o where M is a mass, o is a pulley with it's outter radius r attached to a mass by the belt drive -------. frictionless. 2. M ---------O same setup but the radius is now bigger, R. I was reading...

I've been trying to follow these experiments that NASA is doing to try and warp space-time on a microscopic scale. Obviously that won't have us traveling at FTL speeds yet, but it would be proof of concept. From what I read, they are using a laser, and some kind of special ceramic material (I...

This is a question that I remember hearing a few years ago: If the law were changed so that traffic in Great Britain traveled on the righthand side of the road instead of on the left, would the length of the day increase, decrease or be unaltered? I remember the answer was increase...

Homework Statement There is 14 kg of mass kept on a chassis (consider chassis weightless). Chassis is having 2 identical rear wheels and 2 Steel caster ball wheels at front. Consider the weight distribution to be equal on each of the wheel. All wheels are coupled to a DC motor-gearbox (1:1)...

From my understanding, we are not really moving "anywhere." By this, I mean direction is not absolute. Walking north, in terms of spacetime curvature, is the same as walking south. The only way in which we are moving is through spacetime. A guy going 70mph on a train in Paris is moving through...

Hi, For a long time, it is always unclear for me to understand that there is a tension force acting in the slack side of a belt drive. Tension acting in the tight side is quite straight forward and hence no doubt! When I see a belt drive in motion, I always see the slack side kind of...

Ok. Say you have a belt drive system that is run by a motor at one end. You have a load F located somewhere in the middle of the belt and the belt does not deflect (it is rigid). How would I determine the torque required by the motor to move this load F? Thanks in advance!

I am currently looking at charlieplexing that can in theory cause me to be able to control eight 7 segment displays using 8 microcontroller pins, however in practice there is not enough current to drive all the displays. What I need is to increase the current drive from the microcontroller...

NASA could build a warp drive?!? I just read in a article that NASA has revisited an older theory and found they can improve on it greatly. here is a link to the journal (i guess that is what it is called) of the scientist who is working in this...

Question to the physicists in here: Would it be possible to spin a metal disk such that it increases mass along the outer rim(as all objects increase mass up to infinite mass near the speed of light)? Then oscillate the disk in a tube such that it is spinning while it travels in one...

I know there are quite a few questions about this drive due to the recent news but I have a question that I haven't seen in the other threads. Say we have a working ship that has already formed the bubble of space-time distortion and accelerating towards the speed of light starting from some...

Hey guys could you help me out , so I have built this simple smps project that i needed to the multivibrator part works great frequency is stable square wave but then I have these power mosfets IRFP460 , now the multivibrator has two output each 180 opposite to the other I use each of these...

OK, so I have not read the whole paper, can't seem to access it so if anyone has it, please send it my way or at least a link too it. I understand the principles and with White coming out and proposing how to reduce the mass required I can see it being plausable, interesting at the least. Now...

Had this directed to my attention: How NASA might build its very first warp drive I'm guessing the popular science press is overhyping again. I see a brief mention in the article about "negative vacuum energy" and the possibility of "Casimir cavities" being "a way forward" ... which seems to be...

Hey I have a thing that confuses me. I have a mosfet that has to drive a transformer in pulsed regime. Now I have a multivibrator that gives out 100khz square wave signal and the amplitude of the signal is let's say 30 volts but the mosfet is 330v DC to the Drain and source goes to the primary...

My wife lost a file that she worked directly from a flash drive. Somehow, the whole folder disappeared. Is there any way to recover that folder? Problem is she did not work off the C drive where even you accidentally deleted it, you can find it in the trash bin. She worked directly off the...

Hi. I heard it's possible to use an "Alcubierre warp drive" as a time machine, if they existed. But how, precisely, would that work?

Homework Statement I'm trying to settle an argument about front wheel drive vehicles and acceleration vs inertia and traction. Homework Equations My position is that the faster a FWD car accelerates, the more inertia causes weight transfer off of the front wheels, and onto the rear wheels...

Hi, I have built some stuff before mainly amplifiers and some power supply modules, tell me what you think of this. I want to ask is it possible to have a series lc circuit that is powered from the rectified + rail through a resistor that gives me the correct voltage and transorb that would make...

Displaying Mathematics in Google Drive?? Hey, How can I display math written in word with google drives (cloud storge)? I'm trying to create a google drive for my class at university, but we can't view mathematical equations written in word documents with google drive. Would appreciate some...

Max. speed you can drive on a circular hill an still be in "Uniform Circular Motion" Homework Statement The top of a hill is in the shape of a circle of radius 25 meters. Homework Equations a) What is the normal force that the road exerts on an 1800kg car as it tops the hill with a...

Anyone can help me to calculate the Torque for Drive Pulley of Rolling Conveyor? The details below: - Roller Conveyor : length = 18m (speed of the belt conveyor is 2.5m / sec) - Conveyor consists of 25 roller, 1 drive pulley & 1 tail pulley - Total load of the conveyor : 5,500 kg To move...

Hello, another thread had discussed this, and I have been contemplating the idea for a while, whether it would be possible to use photons to propel a spaceship. I did some calculations to see how it would work and what energy levels we are talking about, and so I'd like if someone who has a...

Hi there, I'm reading a report about the efficiency of the drive train of an electric car. The author recorded the speed and acceleration of the car over a period of time and created the graph below to illustrate the efficiency. Could anybody tell me what the relationship is between the...

Homework Statement We'll be running a vsd water pump. We'll be seeing the energy savings of using a vsd, instead of using an AC motor on full load and using a tap to reduce water flow. Sorry for the lack of info. The Attempt at a Solution I'm sure it will have something to do with...

Hello, I have a few questions regarding machine tool drive and feed back system. Say I have a 1 meter long guide way and a carriage that is driven by DC motor. This carriage glides on air bearings. The drive mechanism has pinch rollers that pinch a drive rod and these rollers are driven by...

Black hole drive in the film "Event Horizon" Cheesy movie, right? A lot of fun though. For those who don't know, there is a starship in the film called the Event Horizon, which utilizes an artificial black hole drive/engine in order to allow it to fold space, although it's probably more...

I was reading this article today: http://news.yahoo.com/warp-drive-may-more-feasible-thought-scientists-161301109.html and in it it states this: How did they come to the figure of 10*C? Is it a matter of energy input to speed output?

I just did a clean install of Windows 7 64 bit on my system. unfortunately I misplaced the box of CDs with most of my applications. I still have the hard drive where all the apps are installed. is it possible to extract the entire application from the old HD and install it on the new one? I have...

Believe me when I say I've done my thinking and just can't call up my thoughts on why I should doubt myself but I'm sure it will come up, and better yet I'd like to hear some ideas. What's it like, how rewarding is it and why, can you find a job? How much is the average pay? How do you know if...

This is driving me nuts and I'm forced to ask this question. The Alcubierre FTL drive model had some limitations, so another physicist whose name began with a D or an N, I think, came up with a revised/improved model. Can you please remind me what it's called? Thanks

Hi everybody! I've been toying around with ideas for using electricity to propel any type of vehicle - gasoline, diesel, hybrid, or electric. The problem is I am not a Mechanical Engineer. So I'm wondering if anybody can tell me whether a drive system like this may be designed to be practical...

Homework Statement A belt drive pulley has a mean diameter of 300mm, an angle of contact of 180° and rotates at 920 rpm. Smaller belt tension is 50 N and coefficient of friction is 0.3 Neglect centrifugal Homework Equations V=piND The Attempt at a Solution pi*(920/60)*0.3=14.45 ms...

Hello, This one has been bugging me for a while. When you drive a car past parked cars that are somewhat close, with the window down, there is a rhythmic whooshing sound. This sounds very much like numerous dopplershifts, but I have difficulty seeing it as a doppler shift because the parked...

I have been sex free (masturbation, porn, etc...) for over 200 days now, but recently sexual thoughts have begun creeping into my head again. I want to decrease my sex drive even more as I find it an annoyance. I have not taken anything thus far. I have been suppressing by sheer will power...