Train Definition and 650 Threads

Howdy! In the middle of reading "The Fabric of the Cosmos" by some MIT physicist or something. I'll present the problem differently than he did because i like my presentation better and it doesn't change the meaning of the problem. There is, on a moving train, a pile of gunpowder. On...

Homework Statement A toy train moves along the track at 9.0m/s. When the power is turned off, the train comes to a stop in 6.0s. The net force on friction acting on the train to stop it is Homework Equations F=ma The Attempt at a Solution how do i find mass and acceleration so...

George took a train at station X with the intention of going to Station Y (which is located 8 kilometers from station X). At the precise instant that the train started leaving station X, the minute hand of his 12 hour analog wristwatch was located precisely on a minute mark. George looked at...

Homework Statement A train consists of of 50 cars, each of which has a mass of 6800 kg. The train's acceleration = 0.08 m/s(squared). Ignore friction and determine the tension in the coupling (a) between the 30th and 31st cars and (b) between the 49th and 50th cars. Homework Equations Net...

If the light clock was on top of the train, it wouldn't be in a inertial system. If a table tennis game was played inside the train, the ball would move as if played on the platform. But it wouldn't be possible ontop of the train. Does the light react the similarly to a table-tennis ball or is a...

What do you guys think would be the best way to trip a camera so that it goes off only for when a train is passing through it? Sorry I can't get anymore specific than that. I was thinking laser tripping device but was wondering if there is anything out there that maybe used that ya'll might...

a moving emitter passes point A traveling at .5 c and emits one photon along the direction of travel. At that same instant a freight train traveling at .5 c passes point A in the opposite direction. Question 1 - two seconds later where is the moving emitter with respect to point A? Question...

I've remembered in bits and pieces a thought experiment that I can't get a grasp on what was suppose to be explained and I was wondering if anyone happens to know what this is. Supposedly this was a famous thought experiment or osmething and I must have been told of it years ago, possibly even...

if you are in a moving train and jump from your position(on the same plane),will you land in the same place where you jumped? train is moving as well as you. frankly,i did jump and see ,since i fell down i could not find out!

Hey I was hoping some would be able to help me or show me how to calculate the amount of force a train exerts on a spot on a track. Simply I could calculate the force exerted on a spot of the track as the weight of the train in kgs times the gravity (9.8m/s^2) will give me netwons of force...

Homework Statement Two trains are heading towards each other on the same track. They are initially 2100 feet apart. The first train has an initial velocity of 88 ft/s due East, the second train has an initial velocity of 107 ft/s due West. Both trains begin decelerating at a rate of a =...

Homework Statement http://img8.imageshack.us/img8/2393/geartain.jpg The Attempt at a Solution I got the right answer, by assuming that \omega_3=\omega_6 , but i don't know why this has to be so. Here's my working: \frac{\omega_2-\omega_3}{\omega_4-\omega_3}=-\frac{N_4}{N_2}...

Homework Statement 1. Homework Statement A train slows down as it rounds a sharp horizontal turn, slowing from 90.0 km/h to 50.0km/h in that 15.0s that it takes to round the bend. The radius of the curve is 150m. Compute the acceleration at the moment the train speed reaches 50.0 km/h...

Hey PF ! I'm planning on doing a "train trip" this summer. I was wondering if you guys had some experience in this kind of thing. I live in Europe but I still don't know if I'm going to travel to some other continent, so feel free to talk, I don't have a very specific plan. Actually I'd...

Homework Statement Three identical train cars, coupled together, are rolling east at 1.13 m/s. A fourth car traveling east at 6.43 m/s catches up with the three and couples to make a four-car train. A moment later, the train cars hit a fifth car that was at rest on the tracks, and it couples...

Homework Statement I have a distance versus velocity graph that gives me the braking distance for a train (for known gradients of track - but gradient is irrevelant for my problem). the graph has distance on the vertical axis and velocity on the horizontal axis. What i want to know is that for...

I would like to make a maglev train for a physics project, but I would prefer it to be simple and for the most part easy to make, as I do not have access to too many supplies. Hopefully, you can help me generate a list of possible ideas with brief explanations on how to construct them and how...

Compound gear train problem (WHY IS IT SO HARD!) Homework Statement http://img5.imageshack.us/img5/1663/problemw.jpg I need to calculate the angular acceleration of the fan at 2600 RPM (motor speed) depicted by figure 4. Homework Equations Sum(torques with respect to input) =...

Homework Statement Stan and Ollie are standing next to a train track. Stan puts his ear to the steel track to hear the train coming. He hears the sound of the train whistle through the track 3.1 s before Ollie hears it through the air. How far away is the train? (Use 5,790 m/s as the speed...

Can anybody please explain why the ball dropped from a moving train appears to take a parabolic path w.r.t the frame of reference of a person standing at the platform? Thanks

Hi, I travel by train nearly every day, and I am using a crappy portable radio connected to my phone (it's just a very small radio receiver built into the earphones) to listen to the radio during the journey. I can't help but noticing two effects, one that can probably be explained pretty...

How come these two functions are used interchangebly? A sampling function is supposed to be a square wave with a very small duty cycle, but at least the height is still finite. A delta function has infinite height and zero width. It seems like both square wave and dirac train are used as...

Suppose one constructs a thought experiment similar to the famous light beam bouncing around a train car. In this experiment a laser and mirror are attached to the surface of a rotating disc such that the beam is sent through the center of the disc. From my understanding of the train experiment...

Homework Statement Liz rushes down onto a subway platform to find her train already departing. She stops and watches the cars go by. Each car is 8.60 m long. The first moves past her in 1.50 s and the second in 1.10 s. Find the constant acceleration of the train. Homework Equations...

Homework Statement You're riding in a very fast train from Chicago to Detroit. In Chicago you set your watch to the correct time, but as you ride through downtown Detroit, you notice that your watch differs from the time shown on the clocks in the station! Are all the clocks in Detroit...

Homework Statement A train traveling at a constant speed rounds a curve of radius 218 m. A lamp suspended from the ceiling swings out to an angle of 16.6° throughout the curve. What is the speed of the train? Homework Equations mv^2/r The Attempt at a Solution I drew a...

What would you have awarded the plaintiff if you were on the jury (and why)? Presumably, the medical (and other related) expenses came up to ~$3.6 million. Or does that include things like "psychological damage"? (I have no idea) More here...

question(s): These are questions from an exam i took earlier tonight, but do not know if i got them correct. 1) Rain is falling with velocity 30 m/s at an angle of 60° from the vertical and is blowing due east. If a passenger inside of a train (also traveling due east) observes the rain...

Homework Statement A train consists of a 4000 kg locomotive pulling two loaded boxcars, the first with a mass of 12,000 kg and the second with a mass of 16,000 kg. Assume that the boxcar wheels roll without friction and ignore aerodynamics. The acceleration of the train is 0.4 m/s2. With...

Homework Statement Eighty per cent of all scheduled trains through Roma Street station arrive on time. If 10 trains go through the station every day, find: a the probability that at least 8 trains are on time b the probability that at least 8 trains are on time for 9 out of the next 10...

Homework Statement A frieght train has a mass of 1.5x10^7 kg. The wheels of the locomotive push back on the tracks with a constant net force of 7.5X10^5N, so the tracks push forward on the locomotive with a force of equal magnitude. (ignore aerodynamics and friction) how long would it take...

Homework Statement When a high-speed passenger train traveling at 158 km/h rounds a bend, the engineer is shocked to see that a locomotive has improperly entered onto the track from a siding and is a distance D = 699 m ahead. The locomotive is moving at 27.2 km/h. The engineer of the...

Lose weight (mass) or train? -- effect of losing weight (mass) on power I'm having troubles wrapping my head around this one (I've provided the example from my class notes below): My question -- how does a decrease in the mass of the rider increase his power producing ability by 18 W...

EDIT -- I posted this here because I figured its more of a conceptual problem than a HW problem, but if people see otherwise, feel free to delete the post. I'm having troubles wrapping my head around this one (I've provided the example from my class notes below): My question -- how does a...

Me and some friends where down the pub and an interesting idea came up. say a fly is flying and collides with an on comming train then the train and the fly at an instant must stop? how can this be? I am trying to think of a way of analysing this. this is my guess. according to Newtons...

Background on The Georgia 300 http://news.yahoo.com/s/ap/20090116/ap_on_go_pr_wh/inauguration_rail_car Originally named the General Polk for a http://en.wikipedia.org/wiki/Leonidas_Polk" . http://community.webshots.com/photo/fullsize/2357037130001227466LPcdUK...

http://epw.senate.gov/public/index.cfm?FuseAction=Minority.Blogs&ContentRecord_id=2158072e-802a-23ad-45f0-274616db87e6 POZNAN, Poland - The UN global warming conference currently underway in Poland is about to face a serious challenge from over 650 dissenting scientists from around the globe...

how come when a train goes through a tunnel your ears pop a little? is it due to the pressure increasing? or are my ears just weird :smile:

Hi, Can anybody offer any assistance with the following problems please: 1. A train is moving along a straight line at constant speed V. Inside a carriage an object is thrown upwards from a height h (measured from the floor of the carriage) with initial velocity v. Determine the trajectory...

A. Jane is standing at a railway switch as an oncoming train rapidly approaches from the left. Just beyond her is a fork in the track. Five innocent people, unaware of the train, are standing on the left fork. One innocent man is standing on the right. If Jane does nothing, the train will veer...

Help With Portable Weigh Station Using Strain Gauge Allright I'm a freshman in college and we have a project due for this semester. The task was to create a weigh station using a strain gauge to measure anything from 2,500lbs cars to 96,000lbs semi-trucks, while giving 100lbs for error...

Many people think of animals as stupid and capable of learning only through conditioning without the ability to make creative leaps. My question is are there any instances where an animal has tried to train a human successfully? Most human would be to blithe to even entertain the notion that...

Homework Statement I need to work out the maximum compression of buffers for a train with 1.2kg mass, traveling at 0.45m/s and the spring constant, k, is 4.8x10^3 Nm^-1 Homework Equations I tried using 1/2kx^2 but I don't know if I am doing it right The Attempt at a Solution I...

Homework Statement a toy train rolls around a horizontal 1.0m diameter track. the coeffifient of rolling friction is 0.10 a. what is the magnitude of the train's angular acceleration after it is released b. how long does it take the train to stop if it's released with an angular speed of...

Homework Statement A train is rounding a circular curve whose radius is 2.00 X 10_{}2 m. At one instant, the train has an angular acceleration of 1.50 X 10^-3 rad/s_{}2 and an angular speed of 0.0400 rad/s. (a) Find the magnitude of the total acceleration (centripetal plus tangential) of the...

Homework Statement You are riding in a train and have just opened a bottle of beer. Prove that for your bottle to be as stable as possible on the table (which is shaking), you should drink sufficient beer such that the surface of the beer coincides with the centre of gravity of the...

A cannon on a train car fires a projectile to the right with speed v relative to the train, from a barrel elevated at angle theta. The cannon fires just as the train, which had been cruising to the right along a level track with speed vt, begins to accelerate with acceleration a. Find an...

Prove that the flange of a train wheel moves backwards in respect to the ground, using the trigonometric functions, linear and angular velocity I really have no idea to go about doing this, all I know is that the proof involves some use of trigonometric functions, linear and angular velocity

Homework Statement A train traveling at a constant speed rounds a curve of radius 200 m. A chandelier suspended from the ceiling swings out to an angle of 17.0° throughout the turn. What is the speed of the train? I am confused about the orientation of the chandelier to the turn and how...

Homework Statement A train is instructed to start at rest at station 1 and accelerate uniformly between points A and B, then coast with a uniform velocity between points B and C, and finally accelerate (slowing down) uniformly between points C and D until the train stops at station 2. The...