Exercise Definition and 578 Threads

Hey, I'm know that PF is not allowed to give medical advice, I do plan to see my doctor next week. Just want to know what you think about this question which is very general anyway. I am quite fit and run and exercise regularly but i also have excercise induced asthma. It is very mild and...

The manufacturers of wood floors need to know how much the wood expands and contracts with changes in humidity and temperature. One way of detecting expansion or contraction is to use a strain gauge. You are required to design a laboratory experiment to investigate how the resistance of a strain...

http://en.wikipedia.org/wiki/Stretching#Possible_Benefits More lifestyle optimization! For the past year, I have basically completely stopped stretching before I run (I run about 5 miles a day). And the reason was basically that Wikipedia article which says that I have not had any major...

In another website (http://www.redhotpawn.com/board/showthread.php?threadid=90807" ) forum the following problem was posted: A man with a hat shows you 3 cards, one completely gold, one completely silver, and one gold on one side and silver on the other. He puts them in his hat, and picks one...

Is anyone else having problems with this? Post some ideas... please?!

I'm referring to question #26 in chapter 3 of Pugh's Real Mathematical Analysis. For those without the book, here's the question: Let X be a set with a transitive relation # (Note: #is just an abstract relation). It satisfies the condition that for all x1,x2,x3 in X, we have x1 # x1 and if x1...

[SOLVED] Proof Thery Exercise Homework Statement Prove the following statement, where m and n are integers: If x = 5m + 6 and y = 5n + 6, then xy = 5k + 6 for some integer k. Homework Equations The Attempt at a Solution X = 5 m + 6, Y = 5 n + 6 X * Y = (5 m + 6) * (5 n +...

Homework Statement In a compact cicrcualr coil "A" (radius R= 25cm),formed by N=150 loops of wire, flows I=10A current. There's another compact circular coil "B" over "A"(radius r= 1.5 cm, loops n= 30) coaxial with "A" distant X ,in which i= 4A flows . in the same direction of "I" (look...

Hi. I'm a math instructor and this problem is given to 1. year economics students. 1. The problem statement In an episode of the TV show "All in the Family", Mike claimed that he could identify different brands of cola by taste alone. He was challenged and presented with three glasses, one...

[SOLVED] Munkres Exercise 22.12 Homework Statement Please stop reading unless you have Munkres topology textbook. Why does Munkres use 3 \delta instead of \delta in part b? I get that replacing the 3 \delta by \delta works fine. Homework Equations The Attempt at a Solution

[SOLVED] N+pi->N+pi exercise in QFT The due date of this exercise was several weeks ago, but I'm still struggling with this. Since some of the QFT exercises are kind of exercises, that are probably the same all over the world, I assumed there could be a non-zero probability that somebody...

Homework Statement An aluminum clock pendulum having a period of 1.00 s keeps perfect time at 20 degrees celcius. (A) When placed in a room at a temperature of -5.0 Celcius, will it gain or lose time? (B)How much time will it gain or lose every hour. Homework Equations I am pretty...

Does anyone know what happens to the internal and external body temperature during and after exercise? I think that internal temperature increases during exercise and then continues to increase..Im not sure..

Homework Statement Let a>b>0 and let n \in \mathbb{N} satisfy n \geq 2. Prove that a^{1/n} - b^{1/n} < (a-b)^{1/n}. [Hint: Show that f(x):= x^{1/n}-(x-1)^{1/n} is decreasing for x\geq 1, and evaluate f at 1 and a/b.] Homework Equations I assume, since this exercise is at the end of...

1. The problem statement I need to prove that if two metrics are related by an overall conformal transformation of the form \overline{g}_{ab}=e^{a(x)}g_{ab} and if k^{a} is a killing vector for the metric g_{ab} then k^{a} is a conformal killing vector for the metric \overline{g}_{ab}Homework...

This is a multi part question so I'll just ask one part. I never understood where the equation for the Fermi Walker Transport came from and I'd really like to understand this because I think it would be really good for pedagogical value and for better understanding parallel transport, maybe...

Whenever I read a corollary, even a lemma, I try to prove it myself first before reading the textbook's proof. This is because I usually find the level of difficulty of the proof comparable to the exercises in the textbook, and thus the textbook's proof is its (correct) solution (which is a...

Homework Statement I can relate tau and X0 by: \tau = \frac{X^0}{2 \sqrt{2} \alpha' p^+ } Why does that mean the angular frequency is \frac{1}{2 \sqrt{2} \alpha' p^+ } ? Homework Equations The Attempt at a Solution

Homework Statement Apparently the answer is sqrt(2 alpha') *4a. But doesn't equation 9.10 imply that the 4a should just be a 1? Homework Equations The Attempt at a Solution

Homework Statement Two forces, F1 and F2, act on the 7.00-kg block shown in the drawing. The magnitudes of the forces are F1=65.9 N and F2=22.7 N. Take the positive direction to be to the right. Find the horizontal acceleration of the block, including sign...

Not wanting to steal the Bow flex thread, I thought it might be fun to post your favorite and and or "most ridiculous exercise device". Late night infomercials have and endless supply of nearly worthless devices...and a few good ones. Gimme a break, is this one for real? How about...

This is an exercise from a book from Serre called Trees. Given the group G = < a, b, c | bab−1 = a2, cbc−1 = b2, aca−1 = c2 > I have to prove G = 1. I don't have a clue. Of course G' = G (commutator subgroup equals the group itself) but I don't know what to deduce from that. Another...

Hello! I'm having a bit of a difficulty trying to solve this exercise mostly because of the resistors. So,when short circuiting the voltage source we have the 20ohm in parallel with 40 ohm right?But what about the other resistors are they in parallel or in series with the result 20//40?The...

Consider a floating point binary notation with 16 bits. From left to right, it consists of 1bit for the sign (0= "+"), e bits for the exponent represented in Excess~2^{e-1} and the remaining bits for the decimal part of the mantissa, normalized between 1 and 2 (1 \leq m <2). a) Calculate the...

Homework Statement Could someone get me started with Exercise 2.5.1 in Shankar's Principles of Quantum Mechanics? Does this forum support TeX or LaTeX? Homework Equations The Attempt at a Solution

Homework Statement Hello! I'm the foreigner so I'm sorry for my English if it won't be good. I have a big problem with one exercise. I think that I have to use Galilean Transformation but I don't know how to start. There is the content: A motorboat is flowing by the river upstream with the...

When a person consumes less than 1000-1200 for a long period of time, their body inturn goes to starvation mode right? And your metabolic rate slows down? Then, by exercising your metablism will increase. If you lower your intake but increase the amount of exercise (or even taken to the extreme...

Please help with the following exercise: Given 2 resistors in series R1=10 ohms, R2= 30 ohms, determine the current flowing through the resistors and the voltage across each resistor, if the potential difference across the wire is V=12V. This is how I solved it: The total resistance Req=...

Please help with the following exercise: How much should the electrical resistance of a light bulb be in order to consume a power of 60W if a voltage of 220V is applied? This is how I solved it: Power= Voltage^2 / Resistance 60W = 220V^2 / R R = 807 ohms Is it correct? Thank you.

Please help with the following exercise: Two conductor spheres with radius R and 2R are at a great distance one from the other. We put a charge of Q=+1.7C on the smaller sphere, and then we put them in contact with a conductor thread. Determine what charge the spheres will have at...

Hi, I need help with the following exercise: Homework Statement We have a square circuit, with 4 capacitors, 1 on each side of the square, all with the same capacitance C. Calculate the total capacitance of the system of capacitors between the two diagonally opposite corners of the square, A...

It is a nice question. It has a few different kinds of proofes. So who is smart here? :wink:

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?

Hey all, First I wanted to say hello, as I am new to this forum. I'm a third-year physics student at the University of Toronto. Anyhow, the question goes like this: We have an exercise ball (one of those large, inflatable ones) with a diameter of 0.7m. If you've ever seen one of these...

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...

Hey there. I've been having this problem and hoping someone has had some experience dealing with this. Everytime I exercise, instead of perspiration coming from my head, I get an itch with a little flakiness instead. My head doesn't seem to sweat anymore. The same itch comes when I go into...

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...

I am doing a first year physiology course and during my studies i have found that the textbook displays very little about renal response to exercise. During a lab experiment, we measured osmolarity and urine amount of a period of 5 20 minute increments after approximately 600ml of water and...

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: