Homework problem Definition and 405 Threads

It's spring break right now, so I thought I'd take the time to brush up on stat mech and thermo before classes resume next week... My question is this (Problem #1096 in "Problems and Solutions on Thermodynamics and Statistical Mechanics" Edited by Yung-Kuo Lim): A flask of conical shape...

The set F of all functions from R to R is a vector space with the usual operations of addition of functions and scalar multiplication. Is the set of solutions to the differential equation f''(x)+3f'(x)+(x^2)f(x)=0 a subspace of F? Justify your answer I know that to prove that the set of...

Homework Statement Find \int \left( \int \frac{x^2-y^2}{(x^2+y^2)^2} \;dx \right) dy. The Attempt at a Solution How would I go about finding \int \frac{x^2-y^2}{(x^2+y^2)^2} \;dx? If I made the substitution u^2=x^2+y^2 how do I go from here?

Homework Statement a singlecard is drawn from a pack of 52 . what is the probability P((oddUblack)Ueven) Homework Equations The Attempt at a Solution P(oddUblack) = 26/52 + 26/52 - 13/52 = 39/52 so is the next part mutually exclusive( if you draw and odd in the first part it can't be even?)...

Homework Statement A golfer finds that when he is at the driving range, he can send the ball a maximum distance of 250m before it strikes the level ground. Once on the golf course, the golfer finds that in order to get a hole in one, he must hit the ball so that is lands a distance of 200m...

George Washington Gale Ferris. Jr., a civil engineering graduate from RPI, built the original Ferris wheel. The wheel carried 36 wooden cars, each holding up to 60 passengers, around a circle 76m in diameter. The cars were loaded 6 at a time, and once all 36 cars were full, the wheel made a...

Homework Statement Part A : A 0.5 Kg ball is attached to a cord 80 cm long. The ball is whirled in a vertical circle at a constant speed. If the ball takes 0.4 seconds to go around once, what is the tension in the cord at the top and bottom of the circle? Part B How long does it take for the...

Homework Statement A has a charge of -2uC, and B has a charge of +3uC. Initially, there is no charge at point P. What is the electric field at point P due to charges A and B? Diagram given below, ignore periods; they were used solely for spacing purposes. ...(0,7m) ....P ....| ....|...

Homework Statement http://img843.imageshack.us/img843/5370/helpxd.jpg Homework Equations Sin law The Attempt at a Solution I got to: F1/sin(105) = F1u/sin(45) = F1v/sin(30) I get F1u = - 219 and F1v = 254.5... It says it is wrong, not sure what I did.

Homework Statement Bill throws a 10.0-g ball straight down from a height of 2.0m. The ball strikes the floor at a speed of 7.5m/s. What was the initial speed of the ball. Homework Equations Can you provide the proper formula and solution to solve this problem? The Attempt at a...

Homework Statement For my class we did a mini-lab that asked us to stand still and long jump. Kind of confused about how to solve because our teacher is horrible. I am supposed to calculate the vertical velocity at take off (which I thought was 0m/s but someone told me it's at the peak of the...

Homework Statement [PLAIN]http://img718.imageshack.us/img718/3508/questionigu.jpg Homework Equations \epsilon = N \frac{\Delta \Phi_B}{\Delta t} = N \frac{\Delta (BA)}{\Delta t}=NA\frac{\Delta B}{\Delta t} The Attempt at a Solution The correct solution must be 6.54 mV. So we...

Homework Statement Block C (m = 4 kg) sits on a frictionless horizontal surface. Block B (of m = 2 kg) sits on top of block C, and is attached to a rope that runs over the massless pulley as shown in the figure. Block A (m = 1 kg) hangs vertically from the rope. With what horizontal force...

Homework Statement Here is the picture: I have an upcoming test, and I cannot seem to get any questions like this one. Help is greatly appreciated. I calculated the net force, such that Fnet=ma. There exists a magnetic force due to the current in the wire. The mass m is negligible, ie...

Homework Statement A 1000 kg weather rocket is launched straight up. The rocket motor provides constant acceleration for 16 s, then the motor stops. The rocket altitude 20 s after launch is 5100 m. You can ignore any effects of air resistance. a) What was the rocket's acceleration during the...

I need some help with this problem. A ball of mass m is suspended from 2 strings of unequal length. The tensions in T1 and T2 in the strings must satisfy which of the following relations? The answer is T1<T2. I can't get a lucite in but T1 is on the left and sloping down to the right on an...

I'm doing some self practice problems for my chemistry class and stumbled upon this question which I cannot figure out. Here's a pic of the problem: http://img843.imageshack.us/img843/126/chemdiagramquestion.jpg" Can someone tell me what they get for the answers?

Homework Statement Question: James and Steve have a contest to see who can kick a football further. James kicks the football at an angle up of 57 degrees, and a speed of 75m/s. Steve kicks the ball with a speed of 100m/s, at an angle up of 48 degrees? Who wins the contest? Vix=75cos57...

Homework Statement A woman stands between a vertical mirror, 0.5 meter tall, and a distant tree whose height is H. she is 1.0 m from the mirror and the tree is 9.0 m from the mirror. If she sees the tree just fill the mirror, what is H? Homework Equations m = (hi/ho)/(-di/do) hi =...

Homework Statement Homework Equations Hi guys would like to know how to star this problem! Any help will be use full thanks The Attempt at a Solution

Homework Statement A \Delta connected induction machine is to start from a source of 480V, 60 Hz. The motor ratings are : 4 poles, \Delta connected, 480V, 60 Hz, X_{ls}\,=\,X_{lr}\,=\,4\,\Omega, X_m\,=\,50\,\Omega, R_s\,=\,0.25\,\Omega, R_r\,=\,0.4\,\Omega. Find the current in the...

Homework Statement |Vp| = \sqrt{}3 Find a vector which is passing through (1,1,1) and (3,4,5) whose magnitude is equal to vector P. I have started studying vectors, and know the vector algebra rules, thought i do not understand the use of coordinates in order to find the direction...

Hello, I have a question regarding enthalpy. I know that when calculating ΔS(o), you just do all of the products minus all of the reactants. However, when calculating ΔHf(o), I am confused as to what you include in the products and reactants? My book is sometimes disregarding some of the...

Homework Statement I have a homwork question that I've been having some trouble with but have come up with a solution.. can someone please verify that I'm on the right path? The homwork problem is here http://i51.tinypic.com/bbeaf.jpg Homework Equationsvx= vocos(theta) vy=vosin(theta)...

Homework Statement Calculate the initial molarity of S2O32- in each trial given that each trial has 1.00 mL of .010 M Na2S2O3 and a total volume of 7.00 mL. Homework Equations mol = g/(g/mol) M1V1=M2V2 The Attempt at a Solution (1)(.01)=7x .0014=x

Homework Statement A large company employs 20 individuals as statisticians, 7 of whom are women and 13 of whom are men. No two people earn the same amount. What is the probability that 6 of the women earn salaries below the median salary of the group? Homework Equations If r is the...

Homework Statement I attached a file containing the problem statement, because it is impossible to reproduce all the symbols. Homework Equations Also in the attached file. The Attempt at a Solution I tried to simply substitute theta but it turned out to be very messy...

Hi, Say if the complementary solution to a linear system is A(coswt, coswt-wsinwt)+B(sinwt, wcoswt+sinwt) and the forcing term is (coswt, coswt-Csinwt), where C is constant How do I tell whether for what values of C is resonance going to occur? Thanks!

Homework Statement Find an equation of the tangent line to y = sin x at the point x = 0. Graph both functions on the same set of axes on the interval [-pie/4, pie/4]. What does this illustrate? Homework Equations y = mx + b The Attempt at a Solution y = sin x ---> y' = cos x...

Not really a homework question; I typed this sum into Wolframalpha and it gave a nice, compact expression, but I couldn't figure out where to begin finding it. Is there a way to find it using just calc II-level knowledge of infinite sums...

Homework Statement See attachment. Homework Equations The Attempt at a Solution I am not familiar with questions like this. The usual op-amp i see have either of the terminals earthed so i need some hints to get started. Thanks.

Show what: sum n.(1/2)^n converges to Now I know that sum (1/2)^n converges to 2 so can I use this some how

Homework Statement A 30.0 kg packing case is initially at rest on the floor of a 1500 kg pickup truck. The coefficient of static friction between the case and the truck floor is 0.30 and the coefficient of kinetic friction is 0.20. Before each acceleration given below, the truck is traveling...

How to display days in order for my clock : Thursday, 12:00 pm Thursday, 2:30 pm Friday, 12:15 am Friday, 12:15 am Thursday, 2:30 pm Saturday, 2:30 pm I don't know how to do that. Con some pody help me out? I have problem in this code ,I couldn't figure out method to display days...

Homework Statement Suppose a spacecraft of speed v_c is in a circular orbit around the Earth at a height H from the surface of the earth. The rocket motor is fired in the opposite direction of motion to reduce the satellite's speed to v_0 and make the orbit elliptical. Let R denote the...

Homework Statement Cerium and thallium ions react as follows: 2Ce4+ (aq) + Tl+ (aq) ---> 2Ce3+ (aq) + Tl3+ (aq) This reaction is very slow and is thought to occur in a single elementary step. The reaction is catalyzed by the addition of Mn2+(aq) according to the following mechanism...

Homework Statement A compressed spring is released pushing a block at rest along a level, frictionless path. This is Location 1. The block then passes over a small area of friction which ends and becomes frictionless again. This is Location 2. The block then enters a loop-the-loop in the...

This is not a homework problem. I just want to have a better understanding of scalar electric potential. In electrostatic, \; V=-\int_A^B \vec E \cdot \hat{T} dl \; where the solution is: V=\frac{q}{4\pi \epsilon_0} \frac{1}{B} Where we assume \; A=\infty. At the same time, \vec...

Homework Statement A girl is pulling a 6.5 kg sled by a rope. The rope make a 35 degree angle with the horizontal. Friction provides a resistive force of 15 N. a) If she pulls with a force of 70 N, what will be the acceleration of the sled? b)If she pulls with a force of 140 N, what happens...

Homework Statement A wagon friction fore is 60N when moving, same for any load its carrying. A horizontal force is applied of 150N causes wagon to be accerate at 5 m/s/s. The same force with a child in the wagon causes it to accerate at 1 m/s/s how do I answer this question to find mass of...

Homework Statement A stockroom worker pushes a box with mass 11.2 kg on a horizontal surface with a constant speed of 3.50m/s. The coefficient of kinetic friction between the box and the surface is .20. What horizontal force must the worker apply to maintain the motion? Homework Equations...

Hello, I have solved the following problem but my answer does not matched with the answer which is written in the book. My answer is 32 m/s but the answer of the book is 37 m/s [PLAIN]http://img842.imageshack.us/img842/6706/projectile.png Could anyone please show me where my mistake is...

Homework Statement A person flying east on September 21 at sunrise hears the time is 2:00PM Greenwich Time. Flying hour after hour at 105 MPH over nothing but water see the the sun set in only ten hours since sunrise. Along what line of latitude have they been flying. Homework Equations...

Homework Statement Well I don't think my teacher explained this very well so I need some help.. Thank you in advance. 26.) A person pushes a 14.0-kg lawn mower at constant speed with a force of F = 88.0N directed along the handle which is at an angle of 45.0(degrees) to the horizontal. a)...

Homework problem stated this: Let S={0,1,2,3,4,5,6} let * be defined by x*y=max(x-y,0) is it commutative, associative, does it have an identity and inverse? help please! I put that yes it is commutative and yes for associative, but I'm not to sure they are right becuase the 6 is...

Homework Statement [PLAIN]http://img194.imageshack.us/img194/2062/57916122.png Homework Equations F_{gravitational}= \frac{MmG}{r^2} F_{centrifugal}= \frac{mv^2}{r} The Attempt at a Solution I got this: dF_{centr} = dF_{grav} \longrightarrow \frac{dm \cdot v^2}{R+x} =...

Homework Statement An airplane flies 142 mi/hr with respect to the air. On this day, the air is moving at 52 mi/hr due north with respect to the ground. What would be the velocity of the plane with respect to the ground,vpg, if the plane were pointed in each of the following directions? How...

This questions has been bothering me for quiet a while Does lim_{x\rightarrow \infty} f(x)=0 \Rightarrow lim_{x\rightarrow \infty} f'(x)=0 if so can you please post a proof because its giving me a headache. If not would it please be possible for you to give me a counter example. Many thanks

A blade parallel faces is 5 mm thick. Taken to a microscope it appears that, to pass on the focus of a surface point to a point on the underside of the blade should move the cannon from the microscope 3mm. What is the refractive index of the material it is made the blade? 5/3 Thx EDIT: Sorry...

Homework Statement State that is either true or false The span of an empty set is empty set Homework Equations n/a The Attempt at a Solution from definition, when you span a subset of vector space, the subset must be non-empty. so, how should i answer this question? should i answer...