Weight Definition and 1000 Threads

In the Kallen-Lehmann spectral representation (http://en.wikipedia.org/wiki/K%C3%A4ll%C3%A9n%E2%80%93Lehmann_spectral_representation) the interacting propagator is given as a weighted sum over free propagators. The pole of the integracting propagator is, of course, given by p^2=m^2, m being the...

I'm doing an experiment and I have to calculate calculate rotational kinetic energy of this can rolling down an inclined plane. According to the equation, Er=1/2Iw^2, I=mr^2, and w=v/r (no slipping effect) right? but doesn't I=mr^2 apply only when the weight is evenly distributed throughout...

Homework Statement Vapor density of a metal chloride is 66. Its oxide contains 53% metal. The atomic weight of the metal is ? Homework Equations vapor density = 0.5 * molar mass The Attempt at a Solution Using the above formula, I found the molar mass of the metal chloride as...

Within an 18-21 gram range, can you produce more force when striking a cue ball with a lighter or heavier cue?

Homework Statement problem #62 Homework Equations Torque = F * radius Tangential accel = radius * alpha w = mg Kinematic equations for linear motion The Attempt at a Solution I tried to find the net torque and go from there. For clockwise torque I got T = 10 * .25 = 2.5 Nm...

If travelers sat on connected lawn chairs on wheels guided by rails pulled by a motor on wheels we might reduce the ratio of rail train weight to that of the weight of passengers carried. An Amtrak passenger train weighs about 200,000 lbs. and holds say 100, 200 lb. people, for a ratio of...

Homework Statement A weight (mass given) is sitting on a beam that is supported by two columns. Given the location of the weight on the beam, calculate the force on each column. Homework Equations not sure The Attempt at a Solution not sure

Homework Statement A study of weight gain in male rats compared two diets, A and B, which were formulated in terms of level and source of protein. A total of twenty two rats were randomly assigned to the diets, eleven to each diet. Summary statistics for the weight gains (grams) by the...

Suppose you put two weights at each end of a string or rope and then throw it away. As we all know the weights will circulate around the center of mass. Now the problem is what is the tension of the string. I am confused about this since there seem to be two contributions to the tension...

My name is Derek Cox, I am new to the forum and I am not an engineer or anything close. I have a degree in flight management and I am a commercial plumber that works on large scale construction projects. Here are my questions but first I will give you some background on the questions. I am...

when a can of coke placed in a sensitive balance is opened what happens to the reading? the answer of this question is given first increases and decreases. can anyone explain this?

Homework Statement An arctic hunter goes hunting polar bears and shoots one. He finds it lying dead on a large patch of almost frictionless ice. He has no scales or weighing device of any kind (and of course, there's nothing to hang it on) but he does have a long rope. How can he get a pretty...

I've read a few books on solving differential equations and they all talk about inner products with respect to weight functions. The examples always read something like that "Using the weight function w(x) = blah blah show that the solutions of the differential equations are orthogonal" We're...

How much weight would I have to carry to equal the resistance I would face swimming in a pool of water? Let's assume I am wearing the same clothing to perform both events.

I am 6'1" and weigh 180 lbs. I need to lose enough wait to get down to single digit body fat percentage. What do u guys recommend in order to lose about 10-20 lbs?

Ok So I have been wondering this for awhile. Could someone help me find an equation to figure this out. I play slowpitch softball and was curious about swing speed and the weight of the bat. If we keep the mass of the ball constant (.198 kg), and the pitch speed constant (8.94 m/s), and...

Ok So I have been wondering this for awhile. Could someone help me find an equation to figure this out. I play slowpitch softball and was curious about swing speed and the weight of the bat. If we keep the mass of the ball constant (.198 kg), and the pitch speed constant (8.94 m/s), and...

Dear native English speaking professionals! Would someone please advise on the term "gross weight load" - is it possible to use it for gravity force of a fully loaded railcar? I use it in the following context: "Estimated vertical force on one chord section is assumed to be equal to...

Homework Statement An air-conditioner unit is fastened to a roof that slopes upward at an angle of 36.0˚ . In order that the unit not slide down the roof, the component of the unit's weight parallel to the roof cannot exceed 520N. What is the maximum allowed weight of the unit...

I need to find the length, weight of the bob and angle to make the pendulum a complete revolution. Kindly help me.

I am needing a project to withstand the impact of a 15lb wood 2x4 traveling at 67mph in a horizontal fashion. I want to test my project before the final test. I want to vertically drop a 15lb wood 2x4 fixed to additional weight at a height of 10ft. The additional weight will be released just...

I've heard that losing weight does not decrease the number of fat cells your body contains. But does this number decrease if you maintain this lower weight over time? I'm thinking that over time, the fat cells die and are replaced at a lower rate.

Can you tell me what spectral weight is? If I have a spectrum that I measure, how can I get spectral weight? For simplicity, assume that the spectrum is a Gaussian curve. Thank you so much!

How to find the apparent weight of objects in a certain latitude? the formula of the apparent weight is R=mg-mrω^(2)cosθ? thank you~

I know it doesn't change mass, but does it change weight? Example: Let's say I put a weight sensor under the road as the car drives on it. Will it feel the same weight if the car stood still and if it drove really fast, or would it feel different weights?

Homework Statement A 43.0 Kg weight is suspended by 2 ropes (imagine a triangle with 〖40〗^0 / 〖30〗^0 angles) Find the tension in each rope. Homework Equations The Attempt at a Solution

Moment -- A weight on a plank Homework Statement A uniform plank of weight 120 N rests on two stools as shown in the link provided below. A weight of 80N is placed on the plank, midway between the stools. Calculate the force acting on the stool at A and B. The answer is 80N and 120 N...

Hello everyone! I am struggling with calculating the normal forces for a vehicle that is in contact with the ground at three places (scoop, front wheels, rare wheels). To calculate the normal forces with two locations (such as front and rare wheel) it is just to balance the forces as well...

Hello all, just a few problems that I've worked through, just clarifying if I'm on the right track. Thank you in advance. 1.) The radius of the Earth is 6378.1 km and completes one revolution per day. Calculate the difference in apparent weight between a person of 65kg mass, standing on the...

Homework Statement find the equation of state which gives the relationship between P , V , N and T C and b are constants Ω = CebNV2(EV)N Homework Equations P/T = (ds/dV)E,N The Attempt at a Solution so i just use s = klnΩ ? then i get ds/dV = k2bNV so P = k2bNVT ? that's it? btw, what...

Hello there, My name is Rick and a couple of my friends are having a discussion at a local rock climbing gym about the weight of a person and whether or not a person who is heavier, works harder than someone who is lighter. Neither one of us are gurus when it comes to physics but would love an...

I want to know the fundamentals of finding the force reqd for moving a stationary object such as a car or a segway (which has got two wheels). Also let me know in a formula mu = F/ NORMAL REACTION, WHAT IS THE VALUE OF A WEIGHT HAS TO BE TAKEN? meaning if weight of a person standing on a...

Hello all, I was just bugged by the fact that you weigh more at either of the poles than you do at the equator. I reason that because at the equator you feel the Earth spinning about it's axis, you would feel an additional centripetal force toward the centre of the Earth ontop of the...

Maybe I'm old-fashioned or stuck up or something, but this really bothers me, and it seems to be a growing trend that people gain weight and become flabby as they get older. To me this seems so disrespectful to your partner. A man or woman was attracted to you based on how you looked when...

Homework Statement The picture below shows a mobile in equilibrium. Each of the rods is 0.16m long and each hangs from a supporting string that is attached one fourth of the way across it. The mass of each rod is 0.10kg. The mass of the strings connecting the blocks to the rods is...

Dear list, Imagine a table of upper surface area S sitting in an open field, with nothing on it. We know that S is subjected to a downward atmospheric pressure P due to a cylindrical column of air of volume V extending vertically from S to the end of the terrestrial atmosphere. Assume this...

Very often we've identified sets of particles with the weights of a semi-simple Lie algebra - for example, the 8 particles of the baryon octet with the weights of the 8 representation of SU(3) global flavour symmetry (in the old days of the Eightfold Way), or the 3 weak bosons with the weights...

Homework Statement A block of mass (m1) is attached by a massless string to a pulley of mass (m2) with radius R. Starting from rest, what is the block's speed after it has fallen height h? Homework Equations I'll call angular velocity w. I'm thinking conservation of mechanical energy, so...

Homework Statement The molecular weight of a monoprotic acid HX was to be determined. A sample of 15.126 grams of HX was dissolved in distilled water and the volume were brought to exactly 250mL in a volumetric flask. Several 50mL portions of this solution were titrated against NaOH solution...

Your probably familiar with the solarsail tech when people use light to push space ships with sails. This is light that is pushing matter with mass, I learned in school that in order to have momentum you have to have mass and light has no mass and therefor no momentum. And if you get hit...

Homework Statement Convolution-Summation of a First Order System with Constant Coefficients http://dl.dropbox.com/u/14655573/1.PNG Homework Equations The Attempt at a Solution The solution from the lecture [PLAIN]http://dl.dropbox.com/u/14655573/2.PNG...

Ok, my apologies if this has been dissected on PF before, I did do a few searches and didn't stumble into anything, there doesn't seem to be much info online. Is it woo-woo or legitimate ? ----- Unexplained Weight Gain Transients at the Moment of Death Journal of Scientific Exploration...

Hello all - I'm new to the forum - I hope some kind person can help with a question of calculating scale weight in a scale model of a glider. I want to test the glide ratio of a glider design by making a 1:4 scale model and thowing it from a certain height at a certain speed and measuring...

An object is pulled up by a rope from an elevator traveling upward with an acceleration of 1.4 m/s2. The tension in the rope is 30N. What is the weight of the object. A) 2.6kg B) 3.6kg C)4.6kg D)5.6kg My attempt: FT=30N asystem=1.4m/s2 Weight of object=mg The system is accelerating up, so let...

Homework Statement you are hovering (no acceleration) in a hot air balloon of total weight (balloon+load+hot air) 18,000 N a) what is the weight of displaced air? b) what is the volume of displaced air? Homework Equations if i knew i wouldn't be asking The Attempt at a...

hello a plane would need a thrust to weight ratio of 1 of fly straight up without losing speed but how can a plane in level flight maintain its altitude with <1 TWR since to maintain a level flight you need to have lift = weight so your engine needs to supply enough power to generate...

Homework Statement http://www.edexcel.com/migrationdocuments/GCE%20New%20GCE/GCE-Physics-6PH01.pdf Q22) Homework Equations - The Attempt at a Solution Look at Q22) I could do a and b but had issues with c) for ci) would I be correct in thinking: - The dotted line is...

Homework Statement So you have a cylinder filled with water sitting on a scale. You take a steel ball and drop it in the water. So does the weight on the scale: 1)Immediately change and stay constant including when the ball comes to rest on the bottom 2)Increase immediately when the...

carry weight?? what does the amount of weight a person can carry depend upon ? i think that it depends upon person to person ?? is there any physical constraint like the weight of the man himself or any other factor ?

1. In the experiment(using a Atwood machine), should the mass of the string be added to the total mass moved by the unbalanced force for better accuracy? Explain. I think the answer is no because the weight of the string is very small and when doing the calculations to find acceleration, one...