Bus Definition and 139 Threads

  1. F

    Synchronous generator on an infinite bus

    I'm reviewing some subjects that I long forgot and now I'm studying synchronous machines. So, when you change the field current (of the rotor) of s synchronous generator, the result is a change in the magnetic flux, which change the internal voltage (Ea). That will result in a change in the...
  2. George Jones

    Is -41C Too Cold for a 20-Minute Walk to the Bus Stop?

    Went for a 20-minute walk to the bus stop. The temperature was
  3. chwala

    Stopping the Bus in 100m - Can it be done?

    Find the question and its solution below; ] Find my approach here; The bus needs to stop at the point where, ##v=0##, therefore we need to find the time taken for the car to come to a stop. using ##v=u+at## ##0=26.67 + (-4)t## ##t##=##\frac {-26.67}{-4}##=##6.6675## seconds The distance...
  4. Aceix

    MATLAB IEEE 13 bus MATLAB/python model

    Hi guys, I'm investigating balancing voltages on a network by injecting or absorbing reactive power with distributed generation. Is there a base python or MATLAB code model I can leverage? Thanks
  5. N

    Time dilation for a simple problem — Light propagating inside a moving bus

    So I drew the problem and tried to derive t1 for an external observer by making the following assumptions. Inside observer sees light travel a distance of d0 meters in t0 seconds at a speed of c m/s. Bus moved Δd meters in t1 seconds at V m/s. Outside observer sees light travel a distance of...
  6. F

    Write MATLAB code to find Y bus for any bus system

    Here's my work: clc; clear all; % Ybus by step by step method for an any bus system % | From | To | R | X | gsh | B | T|ysh % | Bus | Bus | pu | pu | pu | pu | ph-sh linedata = [1 2 0 -5 0...
  7. E

    B How does time dilation affect measurements of wheel rotation on a moving bus?

    Here’s a simple scenario I came up with earlier, because I couldn’t make sense of a few things and so started to feel a bit sick. There’s a bus driving along a road at say, ##v \, \text{ms}^{-1}##, and on one of the tyres someone has painted a bright yellow dot. The tyres have radius of...
  8. anemone

    MHB Solve Math Problem: Number of Passengers on a Bus

    Hi all, this is another math problem that one can use the Singapore model method to solve. All are welcome to post a solution using the method you would like, if this problem interests you. :) There were some passengers on a bus. At the first stop, $\dfrac{1}{5}$ of the passengers alighted and...
  9. nughii

    The Mathematical Model of a DC Bus Voltage on a Microgrid

    I want to compute the dc bus voltage using a programming language, but I doubt the initial value that I should enter. I use the model from this document. This is the explanation about this model Based on my understanding, ##v## is the grid voltage. This value can change. What is the initial...
  10. S

    Engineering Magnetic field near a rectangular bus bar

    An old field theory notebook has given me a formula for a long straight conductor that H = I/2πd which suggests 2.3873T at 0.2mm. Is it a reasonable approximation to use this as a basis for selecting the sensor? Any help much appreciated.
  11. PainterGuy

    Interrupts, bus request operations

    Hi, Could you please help me with the queries below? Please have a look on this attachment. Question 1: It says, "Because the processor cannot know when an interrupt will occur, it automatically saves on the register stack status information about the program that is executing at the time...
  12. B

    Relative velocity between a Bus and a Car

    for part 1: t= d/s = 9000/13 = 692.31s for part 2: What i am unsure about is wether or not this is after the initial observation or exactly what they are asking honestly. so i found the relative velocity of the bus to the car and vice vera and came up with: t=d/s = 9000/4 = 2250s however i don't...
  13. L

    Connect grid tied solar inverter to DC+ Bus of VFD?

    What solutions are there to feeding a high DC voltage rated (eg 1000VDC) certified grid tied solar inverter such as a Yaskawa Solectria PVI23-480; from an alternate DC+ bus supply. For instance the 670 VDC input from a solar string; might be replaced by a a 6 pulse rectifier; (possibly from a...
  14. doglover9754

    Why does water not follow the law of motion?

    So I was in the bus going to school. I sat in the back not directly underneath the emergency exit but more like behind it. Anyways, since it’s been raining consistently, the emergency exits sometimes leak. So I’m sitting down and my jacket sleeve gets wet with a drop from the emergency exit. I...
  15. D

    MHB Scale Drawing: What is the real length of the bus

    QS) A model of a bus has a scale of 4cm to 3m. The model is 10cm long. What is the real length of the bus? my workout: 4cm to 3m. 4 cm is length of model and 3m is real length. so we have, mode = 10 cm long so 4 cm to 10 cm: 10/4= 2.5 cm for real length 3 X 2.5= 7.5 m. I am not sure about...
  16. ThomOnTheBus

    Optical effect seen on a bus: mirrored screen shows different colors

    Hello Physics People, i was on bus 59 lately and i noticed a typical optical effect. There is a monitor/screen in the front of the bus that lists the current and coming stops and updates when you pass one. Its colour scheme is was blue/lightblue/white (see first picture). But when i looked at...
  17. M

    IB Physics Mechanics help? : Bus on an incline

    Homework Statement A bus is traveling at a constant speed of 6.2ms-1 along a section of road that is inclined at an angle of 6.0degrees to the horizontal. a) the total output power of the engine of the bus is 70kW and the efficiency of the engine is 35%. calculate the power to the engine b)...
  18. Alexander350

    Calculating the angle of a bus driving off a cliff

    Homework Statement Homework Equations Moment of inertia Torque Angular momentum The Attempt at a Solution I think I can understand the physics of the situation. There will be a torque on the bus due to gravity while the back of it remains in contact with the cliff and it will start to rotate...
  19. C

    1-D Kinematics Problem (Running to catch up to a bus)

    Homework Statement A person runs at a constant speed of 4.0 m/s to catch a stationary bus. When she is 6.0m behind it (t=0s), the bus leaves, accelerating with a (constant) acceleration of 1.2 m/s^2. How long does it take her to catch up to the bus? Homework Equations X = Xo + Vot + 0.5at^2...
  20. Perico

    B Variation of the classic problem about the student and bus

    Hello, I have a question. There is a classic problem in which a student who is at constant speed approach a bus which has begun to accelerate and is at a certain distance from the student; You need to figure out when it reaches the bus. The problem is easy to solve, if Xo is the distance...
  21. H

    Explanation please -- public bus induction power -- into basic physics?

    Sorry for the title, and sorry if there is already a thread on it. This induction charger for a public transport bus. Can anyone break it down into basic formulas of high school physics. The air gap is frikkin huge. Earlier prototypes apparently had a secondary coil on the bus that was lowered...
  22. A

    Bus Stops Problem: Solving for 4000 Addresses in a City

    Hi all, I have the following problem I need to solve, and I hope you can point me to the right direction. I have a bunch (4000) of people addresses in a city that are mapped to coordinates (longitude and latitude). I also have different bus routes (up to 17), that go through the city picking...
  23. D

    News Bus accident killed 13 Erasmus students in Catalonia

    Maybe you have heard about this horrible accident in the spanisch province catalonia. While there has been some speculation about whether the driver has fallen asleep, I would like to draw attention to another point: The driver seemingly has only been injured slightly. I guess that the students...
  24. M

    Maximum current carrying capacity of Bus Bar

    If I have to transfer 250 MWh through 3 phase aluminium tubular busbar what is the maximum current carrying capacity under normal condition at 80c temperature and voltage is 132kv at busbar from each 60mw 04 transformers 50hz 132/11kv stepup transformers connected on that busbar, this is not...
  25. S

    Continous probability between two bus stops

    Homework Statement You arrive at a road, and all you know is that you are somewhere between two bus stops which are one mile apart. Since you don’t know where you are, you assume that your position X is a uniform [0,1] random variable. a) How far do you have to walk on average to the bus stop...
  26. T

    Simple 4 bus Newton-Raphson matlab not converging

    Homework Statement All the necessary data is in the code, I'm just trying to converge NR, I decided to use the equation S = V^2 / Z since I had the admittance matrix and powers (needed voltages) I think my simple algorithm has a slight issue I can't find. Homework Equations Thank you! The...
  27. L

    Girl running after a bus, kinematic equations.

    Homework Statement Marie is running to catch a bus. The bus has stopped at a bus stop. The bus has the acceleration 0.75m/s^2. Marie has the speed 8m/s. Before the bus starts driving, the space between Marie and the bus is 17.5m. A How long will it take for Marie to catch up to the bus? B What...
  28. N

    Where would you sit in the bus ?

    Homework Statement If there are 4 people and six empty seats . in how many ways can they be seated ? Homework EquationsThe Attempt at a Solution Is it 6P4 6*5*4*3 = 360 combinations ?
  29. Z

    MHB What Time Do the Bus and Truck Meet?

    hi.. the new similar problem : A bus departs from city X at 07:55 am with speed of 80 kmph . and A truck departs from the city of Y at 08:10 am with a speed of 100 kmph. Two cities 260 km distance. At what time did they meet? how to find way out with easy/quickly method?
  30. R

    Relative Motion problem involving a moving person and a moving bus

    1. Problem Statement: What is the velocity of John relative the bus in each of the following situations: A) John is sitting on the street and the bus is moving at 30m/s toward him B)John is sitting in his car traveling North at 25m/s toward a stationary bus? C)John is sitting in his car...
  31. O

    Calculating Transition Probabilities & Expected Values of a Markov Bus Chain

    Homework Statement -A bus is moving along an infinite route and has stops at n = 0, 1, 2, 3, ... -The bus can hold up to B people -The number of people waiting at stop n, Yn, is distributed Poisson(10) and is independent from the number waiting at all the other stops. -At any given stop each...
  32. D

    Motherboard bus speed physical maximum

    I read somewhere (article, messageboard, i can't find it anymore) that motherboard bus speeds are limited because if the frequency gets too high then the signal will disappear. I guess I understood it to mean that the bus wire will become like and antenna if the frequency is too high. They...
  33. R

    MHB How Can You Calculate Bus Arrival Times Using Excel?

    Hello dears I need help with the following: I want to have a schedule for the time arrvial of the public transport buses in my city I would use a formula prediction buses and put in Microsoft Excel, but I have no knowledge to something so complex, so I'm asking for help Since the transport...
  34. Hunter Brandon

    Smart School Bus GPS: Crime, Weather & Traffic Reports

    I have an idea and a small concept of a school bus GPS system that is unique to school buses because it will include recent crime reports in passing areas of concern, weather reports to date, traffic reports to date, and of course the ability to hold multiple destinations at once. With this I...
  35. L

    What Force Caused You to Slide Forward on a Bus? Ans: D) None

    At first I thought it was the force of friction acting opposite the direction of motion, but I was told the answer's D. I'm not sure how you can experience a change in acceleration without there being a force present.
  36. S

    Two Balls on a Bus: Inertia Impact

    Hi I had a question based on inertia if two balls one heavy and one light are on a bus which is moving with velocity v and the bus stops, which ball will move faster and why?
  37. B

    Air Inside Bus: Common Phenomenon Explained

    My doubt is reguarding the common phenomenon observed in the moving bus...While moving in a accelerating bus we all observe the wind gushing inside the bus may it be from the window of the driver or the passenger or even from the doors. My question is if all this air is entering inside the bus...
  38. A

    Hybrid bus simulink motor generator

    Hi, I am making a Simulink model for the drive cycle of a hybrid bus. My bus is using a gas turbine engine to power a generator which then charges the batteries. I have a motor model which I have attached a screenshot of, and I know I can use this as a generator also. I just have no idea...
  39. D

    How can you accurately calculate fault current on a finite bus by hand?

    so calculating FC on an infinite bus is easy but how do you calculate it by hand for a finite bus? here is the concept i am having an issue understanding: let say i have a transformer that is 225KVA with 5%z and 3 phase 480 to 208. with infinite bus i have 12491A available on the...
  40. T

    School bus crash resulting in death

    My sister was recently killed in a car crash, she was the driver of the vehicle, making a left turn at an intersection heading north and was stuck by a school bus that was heading east towards her. The police report claims the driver was driving at a speed of 45 miles an hour at point of impact...
  41. J

    Solving a Bus Direction Change Problem

    Homework Statement A bus traveling at 65km/h on a bearing of 190° changes direction to south-east and continues at the same speed. Find the change in velocity of the bus. Homework Equations The Attempt at a Solution I'm fairly hopeless at drawing the diagrams for these questions so I...
  42. S

    Can Zero MVAR Limits Be Set on a Slack Bus During Load Flow Analysis?

    Question related to Slack bus ( help please ) ! Can we set the MVAR limits of a Slack bus as Zero ( for both MAx. and Min. limits ) during operating load flow program !? and what does the minus sign exactly mean when it's written in the limit , such this one : Qmin. (MVAR) = -42.7...
  43. I

    Relativity: A bus with a vertical windshield

    Homework Statement A bus with a vertical windshield moves along in rainstorm at speed V relative to the ground. The raindrops fall vertically with a terminal speed of V' relative to the ground. At what angle do the raindrops strike the windshield? Homework Equations Kinematics...
  44. B

    Calculating Passengers without Caps or Eye Glasses: 36 Bus Riders

    Homework Statement Out of 36 passengers in a bus. 8 have caps, 2 have both cap and eye glasses , 26 don't have eye glasses, how many passengers have neither caps nor eye glasses Homework Equations The Attempt at a Solution A draw 2 intersected diagrams C and E. In C I write 6...
  45. G

    Generator connected to an infinite bus bar

    Hi. I am supposed to explain using phasor diagram how change in excitation current affects power factor and active power of the generator. I have a few different values for excitation current, real power and power factor. Basically, increasing excitation current causes decrease in power factor...
  46. R

    Does a helium balloon tilt when a bus accelerates?

    Homework Statement Consider a hellium balloon with negiligible mass in the bus with all windows closed. When the bus is acclerating in ##\mathbf a=a \mathbf i##, where ## \mathbf i## is the unit vector in the positive x direction, describe the status of the balloon and explain the reason. If...
  47. B

    Levitating on a bus, would you move toward the back of the bus?

    If you’re on a bus driving at a certain speed, and you could somehow levitate, not touching the ground or the chairs, would you eventually move to the back of the bus or would you stay stationary?
  48. P

    A Woman Running Towards a Bus Which Pulls away

    Homework Statement A woman is running at a constant velocity of 5.0m/s in an attempt to catch a bus. When she is 11m from the bus, it pulls away with a constant acceleration of +1.0m/s2. From this point, how much time does it take her to reach the bus if she keeps running with the same...
  49. 3

    Can Raj Catch the Accelerating Bus?

    Hi! I'm have difficulty with this question. If anyone can help it would be a lot of help. Problem Raj is late for the bus, and as he closes the door to his house, he notices the bus, located 25m away, has begun to accelerate away from him at 1.0 m/s2. Raj begins to chase the bus immediately...
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