Couple Definition and 423 Threads

  1. J

    How Fast Must a Limo Travel Near Light Speed to Appear Shorter?

    hey everyone I'm new here. you all seem great at physics and my teacher gave us these problems and i have no clue as to how to do them! please help me it is due tonight! 1.Natalie designs stretch limo that is 9 m long but appears to be only 5.000m long when driven at speeds near the speed of...
  2. Nebula

    How Do You Solve These Blackbody Radiation Problems?

    A couple Blackbody Problems? I'm a little confused about these two problems involving blackbodies, hopefully someone could give me a bit of insight. Thanks in advance. 1. For a blackbody we there is a frequency peak and a wavelennght peak. Let's call em v and w respectively. Now consider the...
  3. A

    A couple of groovy avatar type pictures I made

    I was bored and started playing with little pictures using Japanese stuff: http://bad-sports.com/~archive/images/avatar.gif http://bad-sports.com/~archive/images/yinyang.gif
  4. F

    I have a couple of brain blocks.

    I've got a U-tube filled with Mercury and water. If I add 11.2 cm of water to the left side, how much does the mercury rise on the right side? For simplicity's sake, D will stand for density, p0 for initial pressure, w = water, m = mercury, h = 11.2 cm for the water and d = the distance the...
  5. Z

    What is the Proof for the Sum of Natural Numbers to n and the Derivative of x^n?

    I'm writing up my maths notes to the computer, while looking over maths notes for series I spotted another way of proving the sum of natural numbers to n (to what I've been taught). By definition: \sum_{k=1}^n k = n + (n-1) + (n-2) + \ldots + (n - [n-2]) + (n - [n-1]) Separating terms...
  6. A

    What Calculations Are Needed to Achieve Equilibrium in These Statics Problems?

    Hi, I have a couple of questions from a statics assignment that I'm in need of help on. Here's what I have so far: http://216.170.11.226/pub/6131.jpg Two rods are connected by a slider block as shown. Neglecting the effect of friction, determine the couple Ma required to hold the system...
  7. E

    A couple of Questions can someone help me?

    Ok I need help with this questions.. would someone be kind enough to honestly answer them? It's a project and I need at least 25 years between two individuals, same questions for the two. I need people older than 21 =-/ and it would really help if I could get at least 1/2 a page typed...
  8. B

    Help with Couple of Calculus Problems

    Hello, I am completely stumped by some of these problems, and have no where else to get help, can anyone help me with these problems? Any help would be greatly appreciated. Thank you very much. 1. The function v(t)=12t(squared) - 16t is the velocity in m/sec of a particle moving along the...
  9. M

    A couple pretty easy integration problems im stuck on

    integral of 10/((x-1)(x^2+9)) dx integral of x^3/((x+1)^3) dx both these are under the partial fraction section, so using those methods would be helpful... thanks!
  10. P

    How Do You Solve These Kinematics Problems Involving Falling Objects?

    Can anyone suggest how to do these problems. 1) A rocks is dropped from a sea cliff and the sound of it striking the ocean is heard 3.4s later. If the speed of sound is 340m/s, how high is the cliff? 2) An apple is dropped and a multi-flash camera is used to take photographs of the...
  11. J

    Help with a couple of questions

    1. What is (integral over all space) delta^3(r-r0)r^2d^3r where d^3r=dxdydz=dV and r0=(0,1,2)? answer: I'm not quite sure what the intergral over all space means.How can r0 be integrated if it's just given as points? 2. Obtain Coulomb's law for the electric field of a point charge from...
  12. Ivan Seeking

    Why should you be careful when choosing the size of a relay contact or fuse?

    Over the years I have run across a few surprising facts about electrical components. I thought to pass on a couple of these [somewhat obscure?] interesting and often important details. So here are a couple of questions to chew on. 1). Why is it bad to oversize a relay contact? In other words...
  13. J

    Understanding Vector Quantities and Projections: Answers to Common Questions

    1. Is every quantity that has three components in three dimensions a vector? From the definition of a vector I think it is. If it isn't, can you give me an example? 2. How can you tell if the projection of a force vector F along the velocity vector v of a particle is a scalar?
  14. I

    Questions About Event Horizon, Singularity & Schwarzchild Radius

    A Couple Questions... I was recently watching a t.v. show and the following terms came up: event horizon, singularity and schwarzchild radius... Can anyone tell me what these things are?
  15. N

    A couple problems with angular momentum

    I know a couple of these I already asked, but I'm really close and missing something. Could someone help?? 1) A ring of mass 2.53 kg, inner radius 6.00 cm, and outer radius 8.00 cm is rolling (without slipping) up an incline plane which makes an angle of = 36.4°. At the moment the ring is...
  16. S

    Effects from Oct 28th CME's wont hit Earth for a couple days?

    This CNN article http://www.cnn.com/TECH/space/ a big solar flare erupted today and it claims some kind of supercharged particles could hit Earth in one to two days….It talks about coronal mass ejections (CME)being associated with solar flares... I guess whatever it is that is predicted to...
  17. M

    What is the height of the tennis ball when it leaves the racket?

    Kinematics in Two dimensions, from Cutnell & Johnson Physics: A tennis ball is struck such that it leaves the racket horizontally with a speed of 28 m/s. The ball hits the court at a horizontal distance of 19.6 m from the racket. What is the height of the tenis ball when it leaves the...
  18. C

    How Accurate Are These Chemistry Calculation Methods?

    Consider this eq, It is balanced: KCN+HCl=KCl+HCN If a sample of 0.140g of KCN is treated with an excess of HCl, calculate the amount of HCN formed, in grams: I just want to know if I did this right 0.140g KCN/65g KCN = x/27g HCN and I got .058 g Another probem: Ammonium Nitrate...
  19. M

    How High Does the Flowerpot Rise and How Long Must the Runner Accelerate?

    Hey can someone help me out with one or both of these questions? 1. A dog sees a flowerpot sail up and then back down a window (height of window is 1.77m). If the total time the pot is in sight for 1.0 s, find the height above the top of the window to which the pot rises. 2. A runner...
  20. M

    Calculating Heights and Acceleration: A Physics Question

    Hey can someone help me out with one or both of these questions? 1. A dog sees a flowerpot sail up and then back down a window (height of window is 1.77m). If the total time the pot is in sight for 1.0 s, find the height above the top of the window to which the pot rises. 2. A runner...
  21. J

    How Do Reflection and Curvature Affect Images in Optics?

    1. Imagine that you are standing 5 ft from and looking directly toward, a brass ball 1 foot in diameterhanging in front of a pawn shop. Describe the image you would see in the ball. -Would I have to find the an answer that tells me that it is inverted, real, virtual, etc? 2. What formula...
  22. J

    How to Calculate Speed and Time for Pions and Spacecraft?

    1. What is the speed of a beam of pions if their average lifetime is measured to be 4.34×10-8s? At rest, their lifetime is 2.60×10-8s. - Would I use velocity= distance/time? 4.34/2.6=velocity 2. A certain star is 70.6 light-years away. How many years would it take a spacecraft traveling...
  23. A

    A couple of basic questions about electromagnetic waves

    Hi, I'm new. From what I understand, radio waves are generated these days using alternating currents or mechanically moving charges. The highest frequencies that modern technology reaches is somewhere in the bottom of infrared. Theoretically speaking, is it possible to emit visible light...
Back
Top