Lost Definition and 564 Threads

  1. G

    Lost Fans: Discuss Show & Its "Scientific Wackiness

    The show is going to be wrapping up soon. It's one of the few television programs I enjoyed. Any fans here? Or do people get too turned off by the scientific wackiness?
  2. D

    Hard Laurent series. A little lost.

    Homework Statement find the Laurent series for \frac{z+2}{z^{5}-8z^{2}} in 2<|z|<\infty Homework Equations The Attempt at a Solution Well, I factored out z^{5} in the denominator, which left me with a geometric sum (since |z|>2). I've come up with...
  3. G

    Power Lost on Restriction in Ductwork

    Hello, I need a formula to calculate how much power is wasted on different types of air filters. A typical application is a residential central air ductwork. A typical pressure drop is 0.1-0.2 inch wg. Typical volume passing through filters is 700-2000 cfm. A typical filter size is 2-3 sq. ft...
  4. C

    Determine the amount of kinetic energy lost due to the collision

    Homework Statement So I am faced with a theoretical equation which uses all variables in terms of Mass,Length,Coefficient of friction which i will just write as u, radius R and gravity g. Block A of mass M is released from rest at the top of an arc ramp which is frictionless it contacts block...
  5. G

    Lunokhod 1 found But why lost in the first place?

    At long last, Lunokhod 1 has finally been http://www.dailygalaxy.com/my_weblog/2010/04/space-detectives-lasers-pinpoint-soviet-reflector-lost-on-moon-40-years-ago-.html" . But why was it lost in the first place?
  6. B

    Where Does the Lost Energy of Redshifted Photons Go?

    Light (photons) that are reaching Earth after traveling billion of years, - the EM-spectre have become redshift. This means that photons must be losing energy. But energy can’t be lost, - so where is that “lost of photon-energy”?
  7. J

    Mass lost in chemical reactions?

    Homework Statement In chemical reactions, when energy is released, mass is lost according to Einstein’s formula just as it is for nuclear energy (though the amounts lost are so small that for centuries scientists thought that mass was conserved). When a kilogram of coal is burned, it...
  8. MikeGomez

    Lost energy of red shifted photons

    Photons which have experienced a change in frequency (red shift) due to gravity(or other red shifting affects), have necessarily lost energy. But total energy is conserved. Can someone please explain in what form is the energy lost? Also related to the red shifted light subject: Electrons...
  9. R

    Archived Oscillator circuit. completely lost.

    Homework Statement An oscillator circuit is important to many applications. A simple oscillator circuit can be built by adding a neon gas tube to an RC circuit, as shown in the figure below. Gas is normally a good insulator, and the resistance of the gas tube is essentially infinite when the...
  10. O

    Calculate the energy lost to friction

    1. Homework Statement http://i43.tinypic.com/i1bq1i.jpg I need help with number 9 2. Homework Equations Wnet=change in KE Wnc=Change in Energy The Attempt at a Solution so I'm assuming the energy dissipated means the work done by friction? so work of friction is umgcos(15)*d...
  11. L

    Lost in the math. Need philosophy to find my way.

    [SIZE="5"]The need for philosophers in science.The greats. The greatest of the greats. Einstein, Lorentz, Darwin, Maxwell, Newton, Galileo, Aristotle. A girlfriend once used to say how much she admired the 1920’s when “men knew how to be men, and women knew how to dress.” We could probably...
  12. S

    Where does the energy go in repelling magnets?

    Two magnet I put nearer to each other in such a way that there is a repulsive force between them. Both the magnets have some potential energy with respect to each other. I keep magnet in this position for a long time & so magnetic field became weaker & so magnet have less amount of potential...
  13. C

    How Do You Solve Complex Third Order Differential Equations?

    Hey all, These are extra credit challenge problems given in my diff. equ. class, and I am in a bit of a rush to figure them out. I tried a few things, but I get lost toward the end. Here are the problems: 1) y'''-y''+y'-y=4sin(x) I did long division with the homogenous equation to...
  14. Z

    How to Calculate Mechanical Energy Lost During a Fall?

    Homework Statement a 6.0kg concrete block is dropped from the top of a tall building. the block has fallen a distance of 55 meters and has a speed of 30 meters per srcond when it hits the ground 1) at the instant the block was released what was the gravitational potenetial energy with...
  15. E

    Using Peng-Robison equation to deterimine fluid lost due to leak

    Homework Statement A container having a volume of 40 L contains one of the following fluids att the given initial conditions. After a leak, the temperature and pressure are remeasured. For each option, determine the kilograms of fluid lost due to the leak, using Peng_robinson equation...
  16. A

    Mass-Light Conversion: How Much is Lost?

    Mass to light ?? Some mass is lost in a star when it burns hydrogen to form helium ( 4H = 1He at more than 7000 C is'nt) ? .. Any calculation how much is lost ?? Even when u burn something which forms flame with are turning some mass into light right or wherelse is the light comming from...
  17. G

    What is the net charge contained within this cube?

    Weve been working as a group on campus now for a few hours and we're lost on these 3. Our teacher did a horrible job explaining this material and the book doesn't do any better of one. A long, non-conducting, solid cylinder of radius 4.7 cm has a uniform volume charge density ρ = 2.1 µC/m^3...
  18. K

    I lost 10/100 points on a physics exam

    and that's because i didnt finish the calculations on the second exercice i had a square root of something and i left it like this, she told me that i had to calculate the square root too, but i didnt have the time and that's why i left it like this if you were the teacher would you do the...
  19. T

    Solve Lost Equations: Bus + Student Acceleration

    Homework Statement A student is running at her top speed of 4.7 to catch a bus, which is stopped at the bus stop. When the student is still a distance 38.2 from the bus, it starts to pull away, moving with a constant acceleration of 0.180 . Homework Equations This is where I am stuck...
  20. T

    Solve 11.28 & 11.25 LOST Homework: dV/dx & Distance in Picture

    Homework Statement 11.28 I have to solve acceleration given the equation for acceleration given the intial velocity=3.6 m/s, and the V equation V=.18V0/x 11.25 I have to find the distance it travels using the information in the picture below Homework Equations The Attempt at a Solution
  21. 1

    Lost in Symmetry and Super Symmetry

    Not getting symmetry at all. I keep reading over and looking for various materials on the subject, but I still can not seem to fully grasp it. Could someone explain what symmetry means in quantum mechanics in a way that a new learner can grasp? This question also applies to super-symmetry...
  22. K

    What happens to the lost energy in these situations?

    What happens to the "lost" energy in these situations? (a) A box sliding across the floor stops due to friction. How did friction take away that KE and what happened to that energy? (b) A car stops when you apply the brakes. What happened to its kinetic energy? (c) air resistance uses up...
  23. C

    Fluids - A lost shipping container is found resting on the ocean floor

    Homework Statement A lost shipping container is found resting on the ocean floor and completely submerged. The container is 6.3 m long, 2.1 m wide, and 2.6 m high. Salvage experts attach a spherical balloon to the top of the container and inflate it with air pumped down from the surface...
  24. S

    Elastic potential energy completely lost to projectile?

    Homework Statement Suppose you have a mass/spring system (with spring constant k) buried underground such that its relaxed (equilibrium) position is level with the ground. Then suppose someone takes a small ball of mass m and compresses the spring a distance xo below the mass/spring's...
  25. 1

    Calculate Initial Velocities & Determine Fault: Skid Data Analysis"

    Homework Statement A H2 was headed North and a convertible Mini Cooper was headed East. Due to faulty traffic signals, they collided, leaving a skid mark 7.6 m long at an angle of 51 degrees North of East. What was the initial velocity of each vehicle and, if the speed limit was 30 mph, who...
  26. P

    Energy lost from a Flywheel to the Environment

    1. A Flywheel (A) mass 100kg and radius of gyration 1200mm rotates 150rpm clockwise. The knetic energy of this flywheel is to be reduced 20% by impacting a second flywheel B rotating at 80 rpm in opposite direction, such that they have the same clockwise angular velocity after inpact. A)...
  27. H

    How is momentum lost in real life?

    Just a quick question about conceptual stuff. How is momentum lost in real life? Is it because of friction or heat? Yet that only affects kinetic energy, which means that momentum should still be conserved. So, what else is there?
  28. drizzle

    Have you ever lost interest in physics?

    Have you ever lost interest in physics?! I’m afraid I have:cry:. I mean I suppose to hand in my thesis last month, but after working as a TA and meeting lots of ‘nerds’ I just lost interest in physics, I know it’s stupid but I couldn’t overcome the feeling, and I don't know what causes it. it’s...
  29. Y

    Ratio of Kinetic Energy lost in a collision.

    For collisions wouldn't the distance traveled during the collision be the same? The energy lost is from heat, sound, deformation, etc. but wouldn't the work done on each car be the same since during the duration of contact they have to move the same distance (as soon as they move different...
  30. I

    Inelastic collision and kinetic energy lost.

    1. A projectile (mass = 0.17 kg) is fired at and embeds itself in a target (mass = 2.43 kg). The target (with the projectile in it) flies off after being struck. What percentage of the projectile's incident kinetic energy does the target (with the projectile in it) carry off after being struck...
  31. S

    Need Help Understanding KE, PE and Mechanical Energy lost due to friction

    Homework Statement A 70 kg base runner begins his slide into second base when he is moving at a speed of 4.0m/s. The coefficient of friction between his clothes and the Earth is 0.70. He slides so that his speed is zero just as he reaches the base. a) How much mechanical energy is lost due...
  32. S

    Calculating Energy Dissipated by Friction

    Homework Statement A 22.9-kg girl slides down a playground slide with a vertical drop of 3.29 m. When she reaches the bottom of the slide, her speed is 1.34 m/s. How much energy was dissipated by friction? Homework Equations I used \DeltaKE + \DeltaPE = 0 The Attempt at a Solution...
  33. S

    Confused lost and demoralised >.<

    Hi guys i am currently a year 1 student and i am doing physics major and i am having a tough time now Even though what i am learning now is the basic of physics, sometimes i find myself lost during lecture and can't make any sense of what the lecturer is saying. Is this a common thing that most...
  34. A

    Calculating Mechanical Energy Lost Due to Friction on Inclined Plane

    Ok so the rpoblem is A 2.20kg box slides down a rough incline plane from a height h of 1.63m. The box had a speed of 2.33m/s at the top and a speed of 1.90m/s at the bottom. Calculate the mechanical energy lost due to friction (as heat, etc.). and I am not sure where to even begin with this...
  35. S

    Calculating Mechanical Energy Lost on Slide for 25.0 kg Child

    Homework Statement A 25.0 kg child slides down a long slide in a playground. She starts from rest at a height h1 of 19.00 m. When she is partway down the slide, at a height h2 of 6.00 m, she is moving at a speed of 9.10 m/s. Calculate the mechanical energy lost due to friction (as heat, etc.)...
  36. H

    Energy lost from Wind Turbines

    What is the effect of wind turbines on the aerodynamic of the wind system? Since energy is conserved, will excessive turbines lead to a leakage of wind energy and transformed into mechanical energy? [or concert to heat?] Also, what is the effect of the local pressure? Thanks in advance.
  37. O

    Lost differentiating a function

    Homework Statement Homework Statement [/b] Hello. I'm trying to solve a non-linear problem and I have been working through the notes on this pdf to try and understand the method before I use it but I get stuck at one of the steps. The pdf is here: http://www.nrbook.com/a/bookfpdf/f9-7.pdf I...
  38. C

    Dimensional analysis, I'm kinda lost

    Homework Statement The Attempt at a Solution I'm really new to this, and the professor didn't explain it well. IDK if I did that right so far, but I'm not sure what to do next. What does it mean by the units of .00256? Thanks
  39. W

    What Secrets Lie Within the Depths of Mount Bosavi?

    Wow it's almost straight out of Jurassic Park, or Jules Verne's novels. http://www.guardian.co.uk/environment/2009/sep/07/discovery-species-papua-new-guinea the giant rat: http://img198.imageshack.us/img198/5349/algratvolcanostill.jpg
  40. D

    Complex Variable Basic Proof by Induction (I'm lost.)

    Homework Statement Use mathematical induction to show that when n = 2,3,..., \overline{z_1+z_2+\cdots +z_n} = \bar{z_1} + \bar{z_2} + \cdots + \bar{z_n} Homework Equations \overline{z_1 + z_2} = \bar{z_1} + \bar{z_2} The Attempt at a Solution So help me get started on the...
  41. B

    New to the physics thing and toldly lost help please

    Homework Statement the speed is doubled and the freq stays the same what happens to the wave length? this is my frist day in this class and i have no idlea where to go with this if someone could help me though this and tell me how to fig stuff like this out it would be great...
  42. S

    Can energy be lost from a Photon?

    Is energy lost from photons when traveling through the air (eg: friction) to an object from a source such as the sun? If so or not, please explain it me simply. Thank you.
  43. P

    A bit lost on the RC circuit differential equation

    Homework Statement Solve the differential equation R\frac{dq}{dt} + \frac{q}{C} = v_0 R is resistance, q is charge, t is time, C is capacitance, and v_0 is the EMF of the power supply.Homework Equations First-order linear differential equation solving method The Attempt at a Solution This is a...
  44. E

    Energy lost by speeding car while drinving on a soft surface

    energy lost by speeding car while drinving on a soft surface how much more energy does a car need to continue driving at a constant speed if it sinks 1cm into a soft material. car weight 1000kg car speed 30mph friction is neglected
  45. A

    Heat question?the amount of heat gained or lost by a substance is equal to

    Heat question!??the amount of heat gained or lost by a substance is equal to Homework Statement the amount of heat gained or lost by a substance is equal to the product of its______ times the change in__________ times its__________ Homework Equations none that i know of The Attempt...
  46. B

    Energy Loss in a Collision: Calculating Speed and Percentage

    Homework Statement A 40.8 g ball of clay hits and sticks to a 3.41 kg block sitting at rest on a frictionless surface. What is the speed of the block after the collision if the initial speed of the ball of clay is 5.04 m/s? b)What percentage of the system's initial energy is lost...
  47. C

    Calculating Bending Moment and Shear Forces in a Beam | Helpful Tips

    Homework Statement Calculate the magnitude of the bending moment and shear forces at the centre of the beam shown in the attached figure Homework Equations The Attempt at a Solution For the shear forces I think its the sum of the vertical components, Bending moment = not...
  48. J

    Finding the fraction of electrons lost

    Homework Statement A small piece of aluminum(atomic number 13) contains 1015 . (The atomic number is the number of protons; it determines the (positive) electric charge of the nucleus and, thus, the number of electrons in a neutral atom.) If the piece of aluminum has a net positive charge of...
  49. F

    Probability: random length of poles, how much is lost?

    Suppose the length of a pole is a random variable X, with mean m(x) and probability density function f(x). Poles are cut to obtain an exact length L. If the initial length of the pole is less than L, the entire pole is lost. If it is greater than L, the pole with be cut down to L, and the...
  50. B

    Maximizing Energy Levels: Calculating Electron Transitions and Photon Momentum

    1. The diagram above shows the lowest four descrete energy levels of an atom. An electron in the n=4 state makes a transition to the n=2 state, emitting a photon of wavelength 121.9 nm (a)Calculate the energy level of the n=4 state. (b)Calbulate the momentum of the photon. The photon is then...
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