Exercise Definition and 543 Threads

The volume of a cylinder, with adiabatic walls and closed at the ends, has been divided in two parts by an adiabatic plate (with unimportant volume), which can slide without friction inside the cylinder (it is like a movable piston). The cylinder has been filled with an ideal diatomic gas...

I tried but I cannot do it. Please help. Two rigid adiabatic containers have inside the same ideal gas, respectively N1=3mol at a temperature T1=340K and N2=2mol at a temperature T2=280K. The two containers come into contact by opening a faucet, and the gas mixes, getting to a temperature T3...

Homework Statement you are in a land inhabinated by people who either always tell the truth or always tell falsehoods. You come to a fork in the road and you need to know which fork leads to the capital. There is a local resident there, but he has time only to reply to one yes-or-no...

i think I've accelerated my learning enough, and now I'm going to start doing problems, problems, and more problems to strengthen my mathematical thinking. this thread will be devoted to munkres' well-used topology textbook. I've done all the problems in chapter 1 so far, and i haven't gotten...

The task here is to verbally describe an abstract work of art. This is quite difficult and I've always been impressed by the powers of description of art reviewers I encounter here and there in art magazines who seem to be able to verbally characterize a given abstract work. In my thread a...

Homework Statement I have the following question to answer: Show that (X^2/h^2)*((1/2*y1) - y2 + (1/2*y3)) + (X/h)*((-1/2 y1)+(1/2 y3))+y2 (sorry about the format) is equal to (taylor expansion): y = y2+(x(dy/dx)¦0 + (x^2/2*((d^2)y)/(dx^2))¦0 Homework Equations also given in...

Do we lose weight through exercise according to that equation? I mean fat is turned to heat during exercise right?

About three weeks ago, I decided it was time to get my lard butt out of the computer chair and start exercising again. I've been swimming three times a week in the mornings before work. I have gotten myself up to about 150m at a moderate pace before I start feeling winded at all, and this...

hi guys am really stuck as i wer off clg ill for quite a while so and desperately need help with what to do as i have not even got a clue where to start! THE QUESTION IS: In this planning exercise you are required to design an experiment, using a sensor and datalogging equipment, to...

I hope someone else finds this interesting, since it through me for a loop for a while. Ok, so time dilation occures in gravitational fields. I used the solution for the time coordinate transformation between "free" space and the space under gravitational influence: t_g =...

Hi, Please can someone help me on how to do this exercise. Give a fundamental matrix for the system: {x'(t)=-y(t) {y'(t)=20x(t)-4y(t) the solution is like: {v1(t)=e2t*cos(4t)[1;4]+e2t*sin(4t)[-1;-2], v2(t)=e2t*cos(4t)[1;4]+e2t*sin(4t)[0;-4]} [1;4]...are colunm vectors. IT is just...

Could some one possible help me with the problem i have for physics, it was a test question and i didn't get it at all. A contestant will be required to pull a 50 Kg landing mat, from rest across the gym floor for 10 seconds. Mat has been selected for this event. he has calculated that if he...

anyone stuck for ideas?

Hi. I'm now studying Lie Groups, and have received the following exercise to solve. I have absolutely no idea where to begin, so please give me a direction. Let U be any neighborhood of e. Prove that any element of G can be written as a finite product of elements from U (i.e., U generates G).

"Prove that in a triangle it is in effect sinA/a=sinB/b=sinC/c Please help me...:confused:

Hi to you all.i have an exercise i cannot solve.i think something is missing. Cylindrical tube V=10L opened at the top has air with a temperature of T1=27 oC.We provide heat to the tube until the temperature reaches the value of T2=327 oC.A)we have to find the amount of air that leaves from...

I've looked through Google and can't seem to find a good site on strengthening the knees. I run a lot on the treadmill so any suggestions are appreciated as well. Thank you

A snake with a little more than 4 meters takes a walk for the forest in the following way. After to walk 1 meter in definitive direction it decides aleatoriamente if she capsizes for the left or if she capsizes for the right or if she continues in the same direction, independently of the...

1. Picture yourself near a stream. 2. Birds are chirping in the cool, crisp mountain air. 3. Nothing can bother you here. No one knows this secret place. 4. You are in total seclusion from that place called "the world". The soothing sound of a gentle waterfall fills the air with a...

I'm a grad student. I've done 2 semester of QFT using Peskin but I've didn't too well due to many reasons. I now want to go back and catch up on things I should have learned better, and then learn even more - I want to be a good field theorist. I'd like to see if there's anyone in a similar...

We've had a couple of exercises on lasers, and there's two I had some problems with: 1. He-Ne-laser Given A He-Ne laser with a 'base wavelength' (might be a bad translation of terminology, for which I apologize) lambda= 632.8 nm; Level width delta(nu) = 1500 MHz ; Allowed deviation...

Hey guys, I was wondering what is the best way to build muscle if I run the track. Is it wise to eat a lot of fat, then run my buttocks off for the muscle? Or eat light and low carbs and low calories? What becomes muscles then?

Hello! Anyone read Apostol's Calculus vol. 1. On p. 28 the exercises feels very hard. Can somebody help me with nr. 2?

Here is all of the question and the help it gives that i need help with: Help the question gives: When lightning strikes a building the results can be very dramatic. The current in the bricks may cause considerable heating of the bricks followed by rapid expansion and failer of the...

I have two questions that were on a (past due) take home test in my GTR class. There maybe many answers, but I am interested in the best answers. 1) Why is Einstien's GTR a theory of gravity? 2) Why is Einstien's GTR a geometric theory? I welcome anyone who thinks they have an...

A ray of light strikes a flat block of glass (n=1.5) of thickness 2.0 cm at an angle of 30 degrees with the normal. Find the distance the light is shifted. I found the angle of refraction to be 19.471 degrees. I figured I could find the horizontal distance traveled by rays going through at 30...

Ow. Just about all I can say. I lifted weights for the first time in the last 9 years today. It's been over 12 hours, and I'm still having problems walking. Particularly up and down stairs. I can't extend my arms all the way. Should have used the lighter dumbells for the curls. On a...

Hello all This is my first time posting in the Philosophy Forums. Nice to meet you all! I was wondering whether any of you practice yoga (Hatha, Ashtanga, Iyengar etc..) What are your opinions about its effects on the human mind and body. I myself have benefited a lot from the practice

It can be useful to construct and try out alternative systems of units---mind-broadening and you can get a different perspective on physics. And in several specialties they do this anyway because it is almost a precondition to being able to think. Whether QFT or Gen Rel they all have their own...

I use a digital pedometer which has pace counting gigure. Four items are displayed: Pace number , pace number by mile, kilometer as well as consumed calories. I need help in finding out : 1. What is the relationship between distance in kilometers and calories burnt? 2.While the pedometer...

I've always kept myself in pretty good shape, I have all of the exercise equipment at home and actually used them every day, until I damaged my knee over a year ago. Now I wiggle and jiggle in places that I shouldn't be wiggling and jiggling. I need to get back into shape but I just...

Velocity from variable force(spring)? What is the velocity of the mass as it breaks contact with the spring? From part 1 I got: A 1.118 kg block is on a horizontal surface with mu-k = 0.150, and is in contact with a lightweight spring with a spring constant of 715 N/m which is compressed...

nuclear physics exercise The activity from a mixed radioactive sample is measured at different times and given in a table like this: Time (h)...Decays/sec ----------------------- 0.0 ...... 7500 0.5 ...... 4190 1.5 ...... 3100 : ...... : : ...... ...

I was trying to learn something about vectors in greater dimensions then only 3. I got this exercise and I couldn't get to it. Can anyone help me? "Let n and a be vectors in R n , and let P = {× Î R n: n . (x-a) =0}. Find an equation in x1,x2,...xn such that x = (x1,x2,x3...,xn) Î P if and...

I really need help with this exercise (it's from a course in basic Fourier analysis). It consists of two parts: (i) Let s_0 = 1/2 and s_n = 1/2 + \sum_{j=1}^{n}\cos(jx) for n \geq 1 . By writing s_n = \left(\sum_{j=-n}^{n}e^{ijx}\right)/2 and summing geometric series show that...

Help! A2 physics planning exercise! Is anyone doing the A2 OCR physics planning exercise? I have just finished the AS one that soooooo many people have been talking about (I am resitting it from last year!) but now have the A2 one to do. It is the one with the surface temperature of the...

Hi! I have an exercise here that I can't solve. Help please. "One of two cylists cycles in the north-west direction at a speed of 8 m/s making an angle of 53 with the west. The other cyclist cycles in north-east direction at a speed of 6m/s making an angle of 37 with the east. How does the...

(--Planning Exercise - Strain gauge Coursework Help!--) Hi I've been stuck for several days in the early stages of my coursework i would have asked my tutor but I have been forced to stay home due to a very bad chest infection :frown: I will first provide a full transcript of the question...

i'm having trouble with this: A spherical raindrop has a charge Q = 3*10^-11. The potential at the surface is V = 500 V (V = 0 infinitely far away). a) Determine the radius of the drop. My first thought was to consider the raindrop as a point charge and then integrate the electric...

Medical Students training exercise... First-year students at Med School were receiving their first anatomy class with a real dead human body. They all gathered around the surgery table with the body covered with a white sheet. The professor started the class by telling them, "In...

I am interested in finding out how often most of us here on PF exercise per week. By exercise I mean deliberate physical activity undertaken to maintain and/or improve fitness. I currently exercise 5 days a week.

Are there any benefits for the mind from exercise, as well as body, apart from on mood?

An Exercise in "nothing" semantics. I apologize for not being able to include the responses, in fact my computer is moving so slowly that I'm not going to be able to copy the exact original post. The point was this: If you take a sentence, where the word "nothing" is used, and replace...