Urgent Definition and 367 Threads

Hi guys - this is going to seem pretty demanding for a first post but I am desperate. I have a series of 11 questions here spanning Energy/Work and Power, Elasticity and Coplanar Forces that I need masses of help with. I'm finding them to be the most difficult questions of any subject I've...

Hi everyone! Im new here and i urgently need help from anyone whos done an OCR Physics sensor coursework. I am not the brightests bulb in the box in physics and i need to essemble a sensor (potentiometer, thermocouple, resistance bridge or a strain gauge) i was told by the teacher if i wasnt...

I need help in the following question: "The rate of increase of the rate of Inflation is decreasing" Write this sentence in terms of derivatives of average prices. My answer: Let p=price t= time therefore, Rate of change of price = dp/dt = Inflation = I therefore...

Here's the problem: " A particle is in its first excited state with energy Ea, before it decays to its ground state with energy Eg by emitting a photon with an energy hbar*omega (omega = 2Pi*frequency) Why will the photon energy be smaller than DE= Ea - E? Show that: hbar*omega = DE...

I have a PDE problem set due on monday and as I look at the teacher's method for solving this problem it doesn't make any sense to me. I'll show what I have so far. Find the solution of U^2U_x + U_y = 0 that satisfies u(x,0)=x So I started out with the characteristic equations...

What is the efficiency of a 265W motor that draws 4.30A from 120V line? How much energy in Joules does this motor use in 1.50 hour? thanks in advance..

hey everyone. I have a question that I cannot seem to work the answer for. the question is. between 1983-1991 X ~ N (20744,8 xxx xxx) Cant exactly remember the numbers, but how do I get the probability that in 1992 the mean will be at least 21000? I have calculated the Z value which...

I got an assignment in physics that is really hard for me, and I am having a lot of trouble even getting an idea. I am supposed to build a car that starts under its own power. I am allowed to have some sort of trigger device. If anyone has done this in the past or they know of links that could...

hi, i posted this question in the probability forum here but no one is even browsing that one. my brother needs to know this but I'm in exam block right now and can only think of the physics I am studying this term. i can't remember how to figure this out anymore i just know i'll probably...

Ok, i missed the class on finding the inverse of a matrix, and i only have a little bit of an idea on exactly what row operations i can do, when i try to make the matrix = its identity. Another question I am stuck on. Q. I have 2 , 3 X 3 matrixs B and C respectivly. The question is find...

:eek: What's your browser homepage?

Hi I have this here matrix A = \left[ \begin{array}{ccc} 2 & 1 & 0 \\ 0 & 1 & 0 \\ 3 & 3 & 0 \end{array} \right] I calculate the eigenvalues and get (2,1,-1) Next I calculate the eigenvectors and get (1,0,1) and (-1,1,0) and (0,0,0) My professor says my third eigenvector is...

Hi every one. Just came acroos a nasty piece and was wondering if you could help me with it. I wasn't sure if it belong to math section or here but science it is for my homework I placed it here. Here is the question. Find the integral of \frac{x}{(x+1)(x-2)^2} I have gotten to some...

Maths urgent help If there is a cubic log with a mass "M" and edges which have a length "2a" and is kept on top of a table,and there is a hole dug inside it right in between two parraral faces of this cube. This hole starts from the middle of one top edge(A) and leads on to the bottom of the...

Hi, as part of my third year degree in Maths I have to give a 10 minute oral presentation of the atom bomb :eek: . I'll start off by quickly giving a historical overview of the experiments that led up to the discovery of radioactivity and the model of the atom etc and then intend to focus on...

I am revising for a test which is next week. I came across this question and I keep getting the wrong answer. Someone please help! A particle has mass 2kg. It is attached at B to the end of two light inextensible strings AB and BC. When the particle is in equilibirum, AB makes an angle of 30...

Have a read and post what you think, Question - Determine the concentration of a saturated aqueous solution of chlorine by back titration. 1. Using measuring cylinders, measure out 25cm3 (enough for reliable results but not wasteful) of chlorine and 40cm3 (excess amount) of reducing agent...

Consider a model in which we let a body fall (radially) into a star, being the simplest example of the schwarzschild solution, in which the angular parts of the solution may be ignored, so that we consider: ds^2 = -(1- GM/r) dt^2 + (1- GM/r)^{-1}dr^2. I have been told that this may be...

I got these two questions i have no idea how to do (i have answers, but no soln's) 1. Given that the affinity constatn Keq for rxn A+B=AB is 5x10^6 and the concentration of free molecules at equillibrium are Afree = 1x10^-4 and B = 1x10^-8, what is the ration of AB to A at equillibrium ans...

The question is: Between two long parallel cylinders of radius "a" and "b" (non-coaxial) and an axal separation of "c", a steady current of "I" flows. (See attachment below) Show that the inner cylinder (radius "a") has a constant magnetic field. Use Ampere's Law. [Hint: 0 = 1 + (-1)]...

Hi I've been working on my assignment for ages and am down to the last two questions (finally) which I've been working on for ages and can't work out. 1. For g(t) = 2sint+cos2t over 0 <(equal to or greater than) x < (equal to or greater than) 4pi show that -3 < g(t) < 3/2 (< greater than...

I have to make this launching device that shoots a projectile (anything I want) in a basketball hoop. I got everything figured out but just need someone to look over my work. The device will consist of a spring inside a pipe. At the top of the spring (where the projectile will be) there will...

Plea for help with kinetics lab -- Urgent I am trying to find a value for the activation energy of the reaction involving potassium permanganate and oxalic acid. I have scoured every free chemistry database on the internet and come up with nothing. Does anyone know how I can calculate this...

Chemistry Speech - Urgent Help! I've got a speech next week upon this topic "outline examples of the selection of metals for different purposes based on their reactivity, with a particular emphasis on current developements in the use of metals". If any-one can help in any matter, little or...

A sample of C10H7OH was found to be contaminated with a small amount of LiBr. The combustion analysis of the sample gave the following results: 77.48% C and 5.20% H. Assume that the only species present are C10H7OH and LiBr, calculate the percentage purity by mass of the sample. First of all...

Our teacher has asked us to verifiy a theory given in our textbook using observations taken by perorming actual experiments using stuff at home or by using ur schools physics or chem lab... the topics we have are kinematics, work and energy, rotational mechanics, gravitation, solid and fluid...

A projectile is fired vertically from Earth's surface with an initial speed of 8.2 km/s. Neglecting air drag, how far above the surface of Earth will it go? I am completely stuck. What formula should i use, this was in the Gravitational Potential Energy /escape speed section

Can someone help me calculate the following problem: I want to find out how many times more intense is 44 decibels compared to 32 db. Example: If in a house the maximal level of sound disturbance allowed is 32db, and the actuall measured sound level is 44db, then how much more intense is...

Hey all, I am stuck on this problem. A spaceship is ona straight line path between Earth and its mon. At what distance from Earth is the net gravitational force on the spaceship zero? Well, when I try to use the Universal law of gravitation. F=G(m1)(m2)/r^2, I could find the...

Dear Sirs, i would like to now exactly the role of these two substances in the process of fat digestion. 1. bile 2.lipase thank you for this lovely site, and i appreciate your kindness and generous to answer me this simple question which confused me a lot. with my regards

What volume of 50% NaOH (by weight) solution is necessary to prepare 1 litre of 0.1M NaOH? Assume that the density of the NaOH solution is 1.53g/ml.

A pair of dice is being rolled. The probability for rolling a sum greater than 8 is 10/36. Is the probability for it taking two rolls to attain a sum greater than 8 just 26/36 times 26/36? I need to make a table of the number of rolls it takes to obtain a sum greater than 8, and the...

an urgent question http://www.fen.bilkent.edu.tr/~ozbay/Phys101-2004/pastfinal.pdf 5th question if anyone can solve please post here very urgent

How do you find the angle between the co-ordinate axis (i.e. the xz plane) and another plane in general?

hi, This has probably been asked and answered a million times before so sorry but here goes. I urgently need help with a Maths University project about the A-Bomb which will include a chapter on Special Relativity and e=mc^2. I have read loads of books but they treat special relativity from a...

I need help solving this problems, is very important. http://bleach-online.com/review.jpg Thanks.!

Please help with the following problem: Do not know where to start! Give an example of two sequences Xn(sum from 1 to infinity) and Yn(sum from 1 to infinity) where lim (as n tends to infinity) of (Xn + Yn ) exists but lim (as n goes to infinity) of(Xn +Yn) does not equal lim (as n goes to...

i need urgent help can anyone suggest some link that clearly states the physical property needed for a stainless steel knife? i desperately need it today. thz any help will be GREATLY appreciated

Partial Fraction!Really Really Urgent Hey I am stuck in this question.Plese help me do this 3/(x^3 +3 ) change this into partial fraction

Imagine there is an object on the surface. The surface is uniform smooth(with same friction over the all surface and friction is greater than 0). Let's define the friction be f. Act a f force to horizontally to the object continuously, it is continuous added. It is obviously stationary...

two astronauts initially at rest in free space, pull on either end of a rope. Astronaut Alex played football in high school and is stronger than astronaut Bob, whose hobby was chess. The maximum force with which Alex can pull, Fa, is larger than the maximum force with which Bob can pull, Fb...

Alright, here's my Q and A. Please verify :smile: By means of a rope whoe mass is negligible, two blocks are suspended over a pulley, as the drawing shows (attachment). The pulley can be treated as a uniform solid cylindrical disk (I=1/2MR^2) The downard acceleration of the 44.0 kg block is...

URGENT what's RCS what is RCS supposed to mean in physics, i have a quiz tommorow with that as a bonus question, i know it has something to do with angles...

This might be an easy problem, but I am missing something and am not sure where to start so here is the problem: A student ties a 500g rock to a 1.0-m-long string and swings it around her head in a horizontal circle. At what angular velocity, does the string tilt down at a 10 degree angle...

Just a question to clear things up regarding to the integrating factors for my exams tomorrow: The standard first order differential equation has the form: dy/dx + p(x)*y = q(x). where the integrating factor is e^(integral of p(x) dx). But in one of the previous year paper, it has...

Suppose that X and Y are independent random variables, where X is normally distributed with mean 45 and standard deviation 0.5 and Y is normally distributed with mean 20 and standard deviation 0.1. (a) Find \ P(40 \leq X \leq 50, \ 20 \leq Y \leq 25). Ans. ~0.5 (b) Find \...

Help Needed! Waves, Urgent! ******Mathematical description of a wave:****** A transverse wave on a string can be described by: Y(x,t)= A cos [k(x-vt)] a) Find the maximum transverse speed vy of a particle of the string. Under that circumstances is it equal to the propagation speed of the...

Hello guys. I have a little problem here.. we are doing a colorimeter (sorry in advance for the english errors. I don't know if it is called like that in english I am translating from french.) experience and I have to use this formula D = e* L * C e= D/ LC where L is a constant 1cm. L=...

Urgent! I really need help please! Sorry for posting this question again. Lemme try to rephrase my question if it helps :frown: . Please help me get started on this question. I am really stuck and time is running out! :cry: I don't want the answer, I just need some pointers to get me...

If you jump from a desk and land stiff-legged on a concrete floor, the chance is good that you will break a leg. To see how this happens, consider the average force stopping your body when you drop from rest from a height of 1.00 m and stop in a much shorter...