Lost Definition and 576 Threads

1. Homework Statement [/b] Two smooth uniform spheres, A and B, are of the same size, but A has twice the mass of B. They are placed at rest on a smooth horizontal table and A is projected directly towards B with speed U. The spheres collide, and then B strikes a barrier perpendicular to its...

I recently bought a toy that has this magnetic disc riding on a metal rail. http://www.fizzicseducation.com.au/online%20store/large%20images/magnet%20rail%20twirler.gif After letting it gain momentum, I tilted it downwards and let it climb and fall (making U shape paths) and then come to...

i was reading a Murray Gell Mann interview and he mentioned that Heisenberg became a crank in his later years. I've tried very hard but I cannot find what Heisenberg was working on. My motivation is, there may be some bits of genius among that pile of crackpottery.

Why is Heat not normally trapped when compressing Air, and reused again in the expansion process of the same air?

We knew energy is lost when a charge accelerates. What is the form of the energy? Which form of energy of theirs are these charges releasing?

Homework Statement I have been currently studying optical activity and i am stuck at this point. The book mentions that the compounds (2,3-Dichlorobutane) shown below are super imposable and its a meso compound: But if we mentally try to keep one structure on the another, the two Cl and...

Hey there... I've been lurking around these forums for about a year now and although I'm not majoring in physics, I figured you guys would still give me some input as to what types of fields I may be interested in pursuing. I guess you could consider this my job research phase of my college...

The wavefunction is defined on the domain of complex numbers. To find the probability of discovering a particle in a certain region, the amplitude of the wavefunction is integrated over that region. The problem is that you have an infinite set of complex numbers mapping to a single amplitude...

Hi all this is my first post. I'm not formally educated in physics concepts but find so much about it very interesting. I registered to ask if this is plausible: It appears we attribute our electromagnetic field on Earth to it's behavior deep inside the planet. There is supposedly a...

A railroad car of mass M moving at a speed v1 collides and couples with two coupled railroad cars, each of the same mass M and moving in the same direction at a speed v2. (a) What is the speed vf of the three coupled cars after the collision in terms of v1 and v2? (Use M, v_1 for v1, and v_2...

Homework Statement ??Homework Equations ?? The Attempt at a Solution I'm not even sure where to begin with this problem...

Energy Lost to Heat ~ Spring (Solved) Homework Statement --->What is the energy lost to heat?<--- spring mass = 15g = .015kg spring constant = 220 J/m^2 spring is compressed 5cm (.05m) then released to achieve maximum height of 102 cm (1.02 m) Homework Equations U = .5(k)(x)^2...

All astronomic objects are periodical deceleration and accelerating. In the deceleration period kinetic energy most be lost, - and will be nowhere to be found, where is it really ? Maybe you will say it is converted to potential gravitionel energy, but the problem is that we can point on it...

Homework Statement Mass m1=6kg traveling with velocity 4 m/s collides with mass m2=16kg traveling with velocity 3m/s in the direction shown (m2= is at an angle of 60degress). If the two masses stick together, find the final velocity of the combined masses, and the kinetic energy lost...

Something is totally not making sense. In a complex scalar field theory, I have two field degrees of freedom, which I parametrize in polar field coordinates: \phi = \rho e^{i\theta}/\sqrt{2}, where \rho and \theta are real-valued; and its Lagrangian takes the form: \mathcal{L} =...

Hi, I'm Jay and I'm new to Physics Forums. I'm an undergraduate student studying physics and computer science. I was wondering what your thoughts were regarding the following photos I took on Google Earth. Edit reason: Maximum number of photos. Thanks very much. My personal opinion is...

Hello, I am new to this forum. I'm sorry in advance if this is the wrong place to post. I am doing a 2nd year math course where I learn about ordinary differential equations and vector calculus. Quick overview of learning objectives for this course can be found here...

Homework Statement A 15.6 kg block is dragged over a rough, horizontal surface by a 68.9 N force acting at 19.7 degrees above the horizontal. The block is displaced 4.59 m, and the coefficient of kinetic friction is 0.286. Find the work done by the 68.9 N force. How much energy is lost due...

Homework Statement We are doing a lab in my physics class. We have to calculate the percentage of Kinetic energy lost in an inelastic collision. I believe that I have the right answer but it seems a little high (44%) the one marble is rolling down a flat track and hits a stationary ball at the...

Homework Statement How much mechanical energy is lost to friction if a 58.1-kg skier slides down a ski slope at constant speed of 12.1 m/s? The slope is 122.3 m long and makes an angle of 10.3° with respect to the horizontal. Homework Equations Emec=KE+PE The Attempt at a Solution...

Hey guys. I'm about to graduate from college with a B.S. in physics from a California State University, and I don't really know what to do next. I used to think the next step was grad school, but now I'm not so sure. My grades are about a 3.1 GPA, I have no internship / real field experience...

Dear Fellows, I purchased a new Laptop with window in it, for activation of that window I gave that laptop to a IT department, that stupid person deleted the orginal window and made partitioning of Laptop from C to C, D, E, F. and installed XP instead of Window 7 . Can I take my...

Homework Statement So, I need a little help with a few problems So, say a 2kg pine cone drops from a tree 41 meters high. If it hits the ground at 10m/s then how much was lost to entropy? Or A 1800kg roller coaster begins at the top of 190m hill, at what height will the velocity be 24m/s...

This is from my text: The existence of the neutrino was first predicted in 1931 by Wolfgang Pauli, when certain nuclear reactions appeared to be violating the laws of conservation of energy and momentum. Rather than modify or discard the law, Pauli suggested that an unseen, chargeless and...

Does the local pressure lost endured in an entrance to a container (k =1) equal to the same local pressure lost of an entrance to a hydraulic Centrifugal pump (in basic hydraulic with mostly ideal conditions - neglecting friction). Or do we ignore it as local pressure lost?

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1. A juniper wood plank measuring 7 ft by 0.5 ft by 0.1 ft is totally immersed in water. What is the net force acting on the plank? () 2. a) F top = P top * A top(l x w) ; b) P bottom = P top + (Dw * h); c) F bottom = (F top) + (Dw*l*w*h); d) Fb = F bottom - F top e) Weight = Dw * l * w...

OK... This is a going to be a LONG post. My apologies for that, and anything that seems contradictory right now. I am probably going to change what I think(I am 18), so take all of this with a grain of salt. I probably don't even know what I talking about. I am not thinking straight. I really...

as title says

Hello! This is my first post but I have been a lurker for a long time! I am starting my own business in the U.S. and have run into a bit of lost in translation when it comes to the electrical requirements needed. I am importing a water system from Hong Kong that is based on: Single...

Given: Mass= 5 kg Vo= 40 m/s Vf=50 m/s s=150 m Ho=0 Hf=50.2 m g=9.8 m/s/s friction=6.26 N θ=30° *You will probably not use all of these values* What percent of initial total mechanical energy is lost during the round trip? (a block (with mass m) going up an inclined plane, and...

I can't find my bank card and its times like this when I think about a device that should be ubiquitous in this day and age. Could you not get a pack of cheap active RFID tags and use a receiver tuned into the particular frequencies emitted by them to tell you the objects distance from where you...

First, a big hello to the Physics Forums community :) Ok, now to business: A car with mass 600 kg accelerates uniformly from rest down a steady hill inclined at 15 degrees to the horizontal[...] - Work out the energy lost to friction after the car has traveled 100m - The average...

I'm currently about half-way (3.5 years) through a Ph.D. program at a top optics program in the U.S., my research is in experimental AMO. I've come to realize that I've lost the passion for research I once had, and really have no desire to enter any career field requiring a Ph.D. I have a hard...

im studying for my circuits midterm and the proff has handouts with questions and answers but not detailed answers. i can't figure out how he went from a fraction to an answer. (-j2)(2+j2)/-j2+2+j2 the answer on the paper is 2-j2 i do not know what I am allowed to do with the 2 next to...

Who would bring a 3-week-old infant to a corn maze? Well this family did, and they got lost...had to call 911 for a rescue once night fell. The police came and sent in the dogs, who had no problem finding the family. http://www.msnbc.msn.com/id/44875752/ns/us_news-weird_news/#.TpYPm94Uqso

Hi! I'm working on problem, where I have to estimate energy, lost due to flue gases, i.e. some amount of natural gases burned in some time period, say [t0;t1]. Burning is used for some material heating. I need to find energy, lost by gases (gases, after combustion), which goes out from flue...

Link to news article: http://news.yahoo.com/video/us-15749625/overseas-jobs-come-home-26850542.html Out of an estimated 4.5 million jobs lost to China over the last few decades, upwards of 3 million are returning to the U.S. Cited factors include rapidly-rising Chinese wages, American...

So high school was easy. I didn't go to an elite high school like many people at my university, but senior year I took 8 ap credits and got by with minimal work. BC calc was easy. I thought it was interesting though...and I thought I was good at math. but I'm not. I found that out quickly in...

Can the % of Energy lost due to friction be negative? Or is it always positive?

Homework Statement At my old university, Calculus was taught much differently than it is where I am now. My old school focused on numerical things, which this school focuses much more on pictures, abstract, etc. and it's very difficult for me. At my old school, we were given a shape...

Homework Statement A lost dog travels 30 degrees south of west for 450m. He ten smells some food and sprints at 20 degrees east of north for 600m. a) draw each vector. Label magnitude and theta. b) calculate the vector components c) calculate the magnitude of the dog's displacement...

I made the mistake of having a Pride and Prejudice moment this weekend. Now I'm pining for Darcy. :cry:

1. Homework Statement I attached the drawing. The force of magnitude F acts along the edge of the triangular plate. Determine the moment of F about point O. 2. Homework Equations M=rxF 3. The Attempt at a Solution What I did was I just picked the top left point of the triangle...

Homework Statement g(f(x)) g(x) = 3/x+1 f(x)= 3x+2 Homework Equations ? The Attempt at a Solution Ive had none I don't even know how to attempt this problem.

Homework Statement I am a bit confused on these two questions in my textbook, I have the answers to them as well. The answer the thermometer question is that the thermometer bulb should be covered in a wet cloth. The answer for the 2nd question is 10.1 MW m^-2. Homework Equations...

Disclaimer: This will be a mixture of fact, logical interpretation and pure opinion. If anyone has any doubt about which is which, please ask... Obama - Obama was the biggest loser here, by a wide margin. He got nothing anywhere close to what he says he wanted, has been forced to utterly...

can someone explain the application of the right hand rule? I'm totally lost. i'd like to understand how it's used

Dear friends, I am here to give you a snapshot of my status, and ask for some guidance. I am about to finish my bachelors in EE from University of Toronto. I have a really bad university track record. I failed first year, then went on vacation for another year out of frustration, came back...

http://www.foxnews.com/scitech/2011/07/11/lost-world-atlantis-like-landscape-discovered/?test=faces (Courtesy NileQueen) It's not the first time to discover land under the ocean, anybody remember the lost city Mega in Cuba? There is another interesting element here, 56 million years...