Urgent Definition and 393 Threads

  1. R

    Solve Tangential Speed Equation: Planet Radius 5.99x10^6 m, G-Accel 7.87 m/s^2

    Homework Statement If the rotation of a planet of radius 5.99x10^6 m and free-fall acceleration 7.87 m/s^2 increased to the point that the centripetal acceleration was equal to the gravitational acceleration at the equator, what would be the tangential speed of a person standing at the...
  2. U

    How Do You Calculate the MOI for a Rod with a Mass Attached?

    Sorry about the somewhat extreme thread but I'm sort of desperate. I missed nearly the whole rotation unit cause of illness and I need to find the MOI for a lab that's due tomorrow. I'm confused about what to plug in where. The lab goal is to find the MOI of a rod of uniform density swinging...
  3. P

    Solve Heat Transfer Problem: Copper & Iron Rods Joined Together

    Homework Statement A cylindrical copper rod and an iron rod with exactly the same dimensions are welded together end to end. The outside end of the copper rod is held at 130 C, and the outside end of the iron rod is held at 0 C What is the temperature at the midpoint where the rods are joined...
  4. R

    Kinematics: Object Thrown Up from 3.6m Window

    Homework Statement 1. an object is thrown vertically up from a window that is 3.6m above the ground. Its initial speed is 2.8m/s. Homework Equations N/a The Attempt at a Solution Is the time the object takes to ascend equal to the amount of time it takes to descend?
  5. J

    Urgent Help Needed: Can't Figure Out Homework Problem

    Can't figure this out! Urgent Homework Statement http://img222.imageshack.us/img222/2470/63809024.png Homework Equations No Idea... The Attempt at a Solution If anyone can solve this then i will be very grateful!
  6. A

    Help With Derivation of Compton Shift

    I am confused in a thing that is on wikipedia and need to know ur answers on this.This is from the last part of derivation for comton shift. From the RHS, you take the square of hf so it becomes h^2 f^2 + h^2f ' ^2 +2h^2ff 'cos theta now how can it take the common from the below...
  7. O

    Urgent Physics HW Help: Parachute, Biking in Windy Day

    If you increase the area of the parachute what would happen? (select all that apply) A. parachute will descend slower B. parachute will move upward C. parachute's drag force will increase D. Nothing changes On the windy day, why is it difficult to ride a bike? (select all that apply)...
  8. S

    Special Theory of Relativity Need help, Urgent?

    Homework Statement An observer in frame S standing at the origin observes two flashes of coloredlight separated spatially by delta x=2400 m. A blue flash occurs first, followed by a red flash 5 microseconds later. An observer in S' moving along x-axis at speed v relative to S also observes the...
  9. H

    Estimating Total Area: Help with Calculating Missing Space on a Flat Plat

    This is not a HW but someone said in a previous thread that it sounds like it so I will post it here because it fits the format I guess. Homework Statement I have a flat plat that is x by y. It has an unknown number of holes in it but I do know the diameter of the holes is D. I also...
  10. K

    Kinetic Coefficient for Polystyrene on Glass - Urgent

    Homework Statement I have searched very long time. I need the kinetic coefficient of Polystyrene of Polystyrene, or even better Polystyrene on Glass. The polystyrene we are using is the stuff that is used to insulate hot water pipe. Homework Equations We do not know the weight of the...
  11. A

    Calculate COP & VCC for Refrigerant - Urgent Help Needed

    COP of a Refrigerant...Urgent Please Help! How do you find the COP ( Coefficient of Performance ) of a Refrigerant if you know the basic details of the refrigerant such as: Critical tempertaure Critical Pressure w Cp Also I am trying to calculate the VCC as well!? Any advice would be...
  12. C

    Solve x: Trig Equation (4/3)sinXcosX-sin22X=0

    Homework Statement Solve for x. x is greater than or equal to 0 and x is less than or equal to 2pi. (4/3)sinxcosx-sin22x=0 If there is a better way to approach this question than the way I did it below, please post it. Thanks.Homework Equations N/A The Attempt at a Solution...
  13. T

    How Do You Calculate Speed at the Center of Mass After a Collision?

    Urgent Help Needed- Finding the speed at the centre of mass? Please help me :( Hi, I was attempting to work through this question. Anyways, I was working from a graph, so the radius 2.5 cm, the two of them collided, it was an inelastic collision as the two objects did part ways, so how do I...
  14. T

    Urgent Help Needed- Finding the speed at the centre of mass? Please help me

    Urgent Help Needed- Finding the speed at the centre of mass? Please help me :( Hi, I was attempting to work through this question. Anyways, I was working from a graph, so the radius 2.5 cm, the two of them collided, it was an inelastic collision as the two objects did part ways, so how do I...
  15. F

    What is the Maximum Load the Steel Bracket Can Support?

    Mechanics Question : Maximum Load needed ?? Urgent Please Help Homework Statement http://img694.imageshack.us/img694/5462/66814773.jpg A new steel bracket was designed to support various loads being hung from the end. The designer would like to know the largest load that can be hung on...
  16. M

    Muon Lifetime Exp: Urgent Qs on Scintillator-PMT Setup

    Homework Statement In using the experiment where a scintillator is connected up to PMTs, and the data is then recorded on the computer... The muon has already lived outside the scintillator for a large amount of time before it decays in the scintillator, so how is it that the experiment...
  17. R

    Solved: Urgent First-Year Calculus Word Problem Help Needed

    Urgent First-Year Calculus Word Problem! Help needed ASAP! Homework Statement Hey this is a first year calculus word problem: A third design question involves our plan to provide interested tourists with a video of themselves on our biggest Ferris wheel. The idea is to place a camera on...
  18. P

    Another Grade 11 Dynamics Problem Needing Urgent Help

    Homework Statement The drag coefficient works like the coefficient of friction when an object is moving through the air, but it increases its effects as the object moves faster. A skydiver plus the parachute has a combined mass of 94.0kg. if the formula for the drag coefficient of the...
  19. P

    How Do I Calculate Friction Force and Mass in This Dynamics Problem?

    Dynamics Problem..Grade 11 Urgent Help Needed! Homework Statement Paul and Mintu are attempting to push a heavy fridge across the kitchen floor. When Paul pushes it with a muscular force of 550N, the fridge accelerates from rest to 28.0cm/s in 3.5s. When Pintu pushes it with a muscular...
  20. M

    Urgent help with inellastic collision problem: finding mass and impact force

    Homework Statement A cart is driving on straight tracks with a velocity of 2 m/s. In the opposite direction, with an angle of 60º according to the tracks, a child with a mass of 2 kg is running with a velocity of 2m/s, he jumps on the cart and stays there. - Find the mass of the cart, if...
  21. B

    Urgent help on a simple instantaneous power problem

    Homework Statement The position of a particle on the x-axis is given by x = 2t^2, due to an applied force of F = e^(2t) parallel to the x axis. a. Write an expression for the power supplied by this force as a function of time. b. Compute the instantaneous power when the particle is at x =...
  22. T

    Solving Electrolysis Questions: NaBr(aq) & Comparing Eo Values

    Here is the question: Predict the products formed at the anode and at the cathode when NaBr(aq) is electrolysed using inert electrodes Answer: Somehow i got 2 different answers by different answer sheets One of them stated that Br2 gas (anode) and H2 gas (cathode) would be liberated...
  23. B

    Urgent help on Friction/Forces problem due tomorrow

    Urgent help on static force at the top of an incline DUE TOMORROW Homework Statement A 5.0 kg block on an inclined plane (angle 37 degrees) is acted on by a horizontal force F with magnitude 50 N. The coefficient of kinetic friction between block and plane is 0.30. The coefficient of static...
  24. H

    How Do You Tackle Complex Problems in Stochastic Calculus?

    Urgent Stochastic Calculus help! Hi, I am new to stochastic calculus and finding some difficulty in understanding things. How to approach the solutions for problem under the topics like martingale, linear diffusion SDEs, expectation of martingale, Ito stochastic integral formulas...
  25. S

    Cracking the Code: Urgent Help Needed for Personal Reasons | 53Xb48ECR1602YL

    For reasons of a personal nature, it's important to me that this code get cracked as soon as possible. I spent a long time on this but I simply can't get - cryptography has never been my strong point. I'd appreciate any help! Thanks so much in advance! 53Xb48ECR1602YL
  26. H

    MATLAB How Can I Recover a Corrupted Matlab File After a Crash?

    Matlab: Urgent! My comp crashed and now I can't open my file anymore... it gives me this error message: http://i31.photobucket.com/albums/c374/haoming/matlab2938293.jpg Please help!
  27. K

    How Do You Calculate Percentage Error in Z When Z is a Function of A and B?

    Homework Statement The quantity Z is a function of 2 variables A and B. Z=A^4/B A=1.253 (error0.005) B=20.7 (error 0.2) Calculate percentage error in Z.Homework Equations I have the relevant error expressions if Z=A/B (errorZ/Z)^2 = (errorA/A)^2 + (errorB/B)^2 if Z=A^n errorZ/Z=n.errorA/A...
  28. S

    Help with Urgent Physics Incline Problem

    Urgent help with physics incline problem! A block of mass m is on an inclined ramp. The coefficient of static friction between the block and the ramp is µs. There is also a wall on the ramp situated below the block (see diagram). http://img15.imageshack.us/img15/6056/image13pj.jpg a)...
  29. F

    Urgent: Understanding Vector Potential from a Straight Wire

    urgent EMM question Homework Statement find the vector potential a distance s from an infinite straight wire carrying current I, check that dell dot A=0 and dellxA=B... ok i know the answer is A=A(s) z, in cylindricals. A(s)=(mu*I/2*pi)ln(s/a)z when a is a constant. can someone please...
  30. L

    Why Can't Stefan-Boltzmann Law Be Explained in Classical Mechanics?

    I've looked all over the internet, and can't find a decent explanation. Could someone please explain why the stefan-boltzmann radiation law of I = oT^4 be explained in classical mechanics rather then quantum? It's urgent, sorry to be pushy. Cheers.
  31. B

    How Do You Calculate Frequency and Period for a Mass on a Spring?

    Waves and Sound Vibrations Question Urgent Please Help?? Homework Statement A mass suspended from the end of a spring vibrates up and down 25 times in 50s. What ar ethe frequency and period of the vibration. Homework Equations F = 1/T T = 2(pie)3.14(squrroot)L/g The Attempt at a...
  32. 1

    Understanding the Isothermal Process: Temperature and Internal Energy Explained

    Urgent!Isothermal process Hi guys. i have a very short question. In an isothermal process, change is temperature is zero, so change in internal energy is zero, thus Q=W. The part that i am confused is that if Q=mc(deltaT) then should be a change in temperature in the isothermal process? Thanks...
  33. O

    What Is the Bandwidth of a 1kHz Modulated 146.52MHz Carrier Using Carson's Rule?

    Urgent...Communication Question Homework Statement A 1kHz sinusoidal frequency modulates a carrier at 146.52MHz with a peak deviation of 5kHz.Evaluate the exact magnitude spectra of FM signal if Ec=1. Sketch your result. Using carson's rule, evaluate the approximate bandwidth of the FM...
  34. L

    Find Acceleration of Uniformly Accelerating Car | Kinematics Homework Help

    Homework Statement A car that is accelerating uniformly travels 18 m in the fifth second of its motion. Calculate acceleration. I've tried to answer this a million different ways. If it's in the fifth second on motion that means it has traveled for four seconds, yes? And I'm not sure...
  35. R

    Help Needed: Urgent Calculus Project - When the World Will End

    Hello ladies and gentleman. I need help ONLY because...my project is due tomorrow. BUT dear sirs and siresses, do not fret. I only need some help in some areas (let us hope). My project is entitled When the World will End. I wanted to make a somewhat, vague creative project, so I chose this...
  36. V

    How to Find 'a' Value in Quadratic Graphs

    can someone pls tell me how you can get the value of 'a' or the gradient in a quadratic equation by analysing the quadratic graph as a reminder the equation is y=ax^{}2+ bx + c
  37. A

    MATLAB How to Integrate Step Plot into a MATLAB GUI Button Callback?

    MATLAB : Step Plots [Urgent] I am stuck at very crucial stage. I want to generate the step plot which is generated using step command in simple MATLAB environment. However, I am trying to incorporate it in GUI where it should plot the step plot when clicked on the button. Following is the...
  38. L

    Solve de Broglie Wavelength of Atoms in eV: Urgent Help

    Homework Statement http://www.strings.ph.qmul.ac.uk/~russo/QP/r06QPHYEX.pdf Question 3. The Attempt at a Solution I can easily derive the equation I need, which is: lamda = h/p Which after some playing around with K.E =1/2mv^2 etc we obtain: lambda (de brogile) = h/SQRT(2mKE)...
  39. L

    Integrate (x2 - 1)/(x2 + 1): Lunar Guy's Question

    1. Integrate on the interval [0, 1]: (x2 - 1)/(x2 + 1) 2. No relevant equations. 3. S x2/(x2 + 1) - [S 1/(x2 + 1)] = S (x2 + 1) - 1/(x2 + 1) - [(arctan x)] = S -1 - [(arctan x)] = -x - arctan x I can plug in the numbers on my own, but I would like to know if what I've done...
  40. L

    Solving Quadratics: When to Use Each Quadratic Equation?

    I've been having trouble understanding why my answers are always different to the solutions and I found that there's two equations: {-b ± SQRT(b^2 - 4ac)}/2a and {-b ± SQRT(b^2 -ac)}/2a I don't know when to use either equation, always having used the first, and for someone at my level to...
  41. P

    Solving Hybridisation: 2pz, 2px, sp3, 2py Bonds

    The problem is as follows: Decide if the following pairs of orbitals overlap to form a σ bond, π bond, or no bond at all. Explain your reasoning in each case, including a sketch of the orbitals. Assume the bond lies along the z-axis. (a) 2pz and 2pz (b) 2py and 2px (c) sp3 and 2pz (d)...
  42. R

    How Do You Calculate Motor and Drive Specifications for a Construction Lift?

    Urgent calculation: design a construction lift... the construction lift is used in a building construction project. the construction will raise building materials from ground level to any height up to 12.2m. The life will be at the top of a rigid scaffold that is not a part of the design...
  43. R

    Design a Construction Lift: Urgent Calculation Solution

    Urgent calculation: design a construction lift... the construction lift is used in a building construction project. the construction will raise building materials from ground level to any height up to 12.2m. The life will be at the top of a rigid scaffold that is not a part of the design...
  44. C

    Solving an Urgent Elastic Collision Question: Finding the Value of k

    Hi I am really stuck on the following and have an exam on it in 2 days. Can somebody please help me. A particle of mass m collides elastically at an angle of 90 degrees with a lighter particle of mass km. Initially both particles had a speed u. After the collision the particles move apart...
  45. C

    Solve Urgent Rotation Question: mva, T in Terms of N and M, a, R

    Hi I am really stuck on the following and have an exam on it in 2 days. Can somebody please help me. I have attempted it but think I have done it all wrong. (I have indicated how many marks each part of the question is worth at the side). a. A particle of mass m moves at constant velocity v...
  46. D

    Engineering Help with Circuits Capacitance & Inductance

    The images tell it all. Please help someone. http://image.cramster.com/answer-board/image/200941884006337564080009162509346.jpg on this diagram, the expression IL(t) should read I(t). http://image.cramster.com/answer-board/image/2009418845296337564112974787505740.jpg
  47. P

    Proving the Squeeze Theorem for Sequences

    Homework Statement Prove that if X[n]->L, X[n] doesn't equal 0 for all n, L doesn't equal 0 and Y[n]->M, then (Y[n]/X[n])->(M/L). Homework Equations They only give you the squeeze theroem and that if X[n] converges then it's limit is unique. O and the definition. A sequence of reals has...
  48. A

    How Can Bubble Sort Optimize PCB Drill Bed Movements?

    Urgent help need ! Bubble sort ! hi all, I was asked to built a C programme using bubble sort. here is the Question. TASK A PCB manufacturing company requires a software program to convert a series of a table of drill data to minimise the movement of the drill bed to speed up production...
  49. C

    MATLAB Matlab Code for Matrix Multiplication

    Hihi, Let's say I have the linear equations ,A 2x +3y +4z 5x+6y-7z 5x-4y+3z then I can always write as a matrix multiplication A= B*x matrix B = 2 3 4 5 6 -7 5 -4 3 times matrix x x y z Then., how can I tell MATLAB to express in the matrix multiplication form so...
  50. L

    Urgent need Help on Chem (average velocity, Thermochemistry, ionization energy)

    Urgent need Help on Chem... (average velocity, Thermochemistry, ionization energy) 1.) The average velocity of Cl(2) molecules is 2.50 x 10^3 m/sec at a temp of 25 C therefore the average velocity of helium atoms is ?? [ i got the answer 1.05 x 10^4 m/Sec] but I am not sure 2.) A gas is...
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