Stuck Definition and 858 Threads

You're stuck on a crossword clue or something and the answer is on the tip of your tongue but you just can't get it out?What do you do? I find it helps to walk slowly up and down with a slight rocking motion and with the hands held tightly behind the back whilst mumbling like an idiot. Try it...

I accidently got into AM radio mode in my car for the last two days, and I can't figure out how to take it back into FM because there isn't a stupid AM/FM button. I had to have hit some funky combination of buttons to go into AM and now I am stuck. ANYWAYS, I've been stuck with this AM radio for...

Homework Statement Define specific heat capacity and latent heat of fusion. Copper melts at a temperature of 1356 K with a latent heat of fusion of 210,000 J/kg (Joules per kilogram). Calculate the thermal energy required to convert a copper bar with a mass of 40 kg at a temperature of...

stuck on light intensity problem... 1. Homework Statement http://s685.photobucket.com/albums/vv212/dewdr0p714/?action=view&current=physicsexam2q5withoutphotocell.jpg A conducting rod slides down 2 frictionless copper tracks at a constant velocity. There is a .50 T magnetic field...

Homework Statement Prove that the area of an ellipse with equation \frac{x^2}{a^2} + \frac{y^2}{b^2} = 1 is A=\pi ab. Homework Equations The Attempt at a Solution I solved for y, set up the integral for area with lower limit -a and upper limit a, did u substitution...

Homework Statement Integrate -9e^x - 28 / e^2x + 9e^x + 14 It gives a hint which is substitute u = e^x. Homework Equations The Attempt at a Solution I want to integrate by partial fractions if possible... however before I can do that, I need to make the substitution, and I...

Kirchoff's Rule...problem stuck! Homework Statement http://img5.imageshack.us/img5/5307/physishelp.jpg The Picture Explain above explains it all, I have attached a same file if you might need it! It is the same picture. Homework Equations V=IR Thats all I know! The Attempt at a Solution...

Homework Statement Hey guys. So I've got half a ball from 0 to point A as you can see in the pic and I need to calculate the potential of the ball at point A. So what I did is to break it into disks. I found the differential potential of a volume ring which is inside the disk at point A...

Hi, first post here. I've been trying (out of personal interest, not homework) to re-derive http://www.springerlink.com/content/mm61h49j78656107/" relatively famous calculation on the ground state of Helium from 1929. And I'm stuck at one point. What Hylleraas did, was to parametricize the...

please help with this construction question I am really stuck! question is:- a reinforced concrete beam is to be 700mm deep. the minimum width of beam is to be used and 20mm size aggregate has been specified. three 25mm diameter bars have been calculated for tension reinforcement and three 16mm...

Hi, I am torn between these two majors that I will absolutely love. Here are the basics: CS: I think that I would enjoy programming (although at this point, all I really know is a little java), and I like solving puzzles. However, I think that CS might be a little too theoretical for me...

Homework Statement Integrate (sin5x)(cos4x)dx Homework Equations The Attempt at a Solution I tried substituting u as (sin5x), but wound up with something way more complicated than what I started with. Same thing happens if I substitute cos^4 for u. I have no idea what to try...

Hi, I am also having trouble with the hockey puck question. A hockey puck rebounds from a board as shown in my diagram. The puck is in contact with the board for 2.5 ms. Determine avg acceleration of the puck over the interval. Vi = 26 m/s Vf = 21 m/s I tried the cosine law but I keep...

Can you help me solve this equation? Its the Gompert equation, dp/dt=cln(K/p)p. I used substution to get -ln(u) = ct+b, where c is a constant, and bi s a constant of integration. Next we have -ln(ln(k/p)) evaluated from pt to po = ct+b Then ln(k/p) from pt to po = Bexp(-ct). This is...

Homework Statement You are trying to loosen a stuck bolt on your RV using a big wrench that is 50 cm long. If you hang from the wrench, and your mass is 55 kg, what is the maximum torque you can exert on the bolt? Homework Equations T=Fr I did T=55kg*.5m The Attempt at a...

The question: A grasshopper makes four jumps. The displacement vectors are (1) 27.0 cm due west (2) 23.0 cm, 35.0^{o} due south of west (3) 28.0 cm, 55.0^{o} south of east and (4) 35.0 cm, 63.0 ^{o} north of east. Find the magnitude and direction of the resultant displacement. Express the...

Homework Statement Derive the compton equation. Homework Equations \lambda` - \lambda = h/ mc (1 - cos\theta) E = hf = hc/\lambda The Attempt at a Solution Okay, I'm sorry this is so long, I'll try and make it as concise as it is possible for a whole blather of random crap to...

hello i am stuck on the following: A=cos(-20)-K1-K2cos(-20)+K3 K1=3.825 K2=2.295 K3=2.514 A should equal 2.922 but somehow i can't get it to equal that i have tried using my calc in radians and degrees mode but neither come out with the right answer please help me!

Hi, I was trying to solve the following integral, but i don't seem to get anywhere. \int_{0}^{\infty}ln^2(\frac{x^2}{x^2+3x+2})dx I played around with it, but got to a dead end each time. At some point i get to integrating the following, which seem equaly difficult: \int...

a block of mass 2.0 kg is placed on a compressed vertical spring that is compressed .050m. (The spring and the block are not attached) The spring is released, and it propels the block vertically upward. when the block has risen .60m abovie its initial position, its velocity is 1.7 m/s. how much...

Homework Statement what is the limit of as x approaches 9? Homework Equations The Attempt at a Solution I'm stuck please help...

acceleration. linear motion. I'm stuck! Homework Statement a train moves at a velocity of 60 m s-1 and stops after a distance of 600m. what is its deceleration?Homework Equations v=s/t The Attempt at a Solution this is my working: u= 0 m s-1 v= 60 m s-1 s= 600 m v=s/t 60=600/t t=10 s ...and...

What animals can naturally expel small nonselfs which penetrated into their flesh and were stuck right there from their bodies? I wish to mutate to be so, who can help me?

Homework Statement http://www.webassign.net/walker/p11-78alt.gif An 85 kg person stands on a uniform ladder that is 4.3 m long and weighs 65.0 N. The floor is rough; hence it exerts both a normal force, f1, and a frictional force, f2, on the ladder. The wall, on the other hand, is...

One cold winter day, a tractor gets stuck in a ditch. The operator hooks a tow chain to a nearby tree and attempts to move the tractor by jumping up and down on the chain. If the chain is 10 meters long and is stretched level one meter above the ground, and the tree is stationary, how far does...

Homework Statement What minimum energy is required to raise a 1.7e3 kg vehicle from the surface of the moon to a height of 5.22e6 m? Homework Equations Ep= -G(m1m2)/r The Attempt at a Solution Ep(initial)= -6.67e^-11(1.7e^3 x 7.35e^22)/1.74e^6 = -4789750000 Ep(final)=...

Can someone give me a hand with these questions because I am really stuck on these! I am stuck on both these questions, I have no idea where to begin I was given a worksheet which our instructor will review with us but I would like to know how to do them before class. I finished most of it but...

Homework Statement the barrel of a rifle has a length of 0.916m. a bullet leaves the muzzle of a rifle with a speed of 642 m/s. (note: assume the acceleration in this is constant) what is the acceleration of the bullet while in the barrel? answer is m/s^2 Homework Equations uhm i...

Can someone else me please I am so stuck on these questions! I am stuck on both these questions, I have no idea where to begin I was given a worksheet which our instructor will review with us but I would like to know how to do them before class. I finished most of it but this I am stuck on. Can...

Hi, i think I've got the first part of this question done but I am stuck with the rest, so i'll post the lot in case you think i have the first part wrong. a) Derive and expression for the work done by an ideal gas when it expands isothermally at temperature T from a volume V1 to V2. b)...

Homework Statement Hi, I am reading Ray d'Inverno's book, 'Introducing Einstein's Relativity' and there is a particular derivation of the geodesic equation that I get stumped on (chapter 7). It is a variational method and the final equation is df/dx_alpha-d/du{df/dx_alpha_dot}=0 where...

Homework Statement integral of (x^2)*sqrt(6x+7) from 0 to 1 The Attempt at a Solution i am thinking this has something to do with u substitution but i can't figure out what u should be?

Homework Statement Manipulate equations 1-3 to show the formation of the overall equation 4. Equation 4: HCl + NH3 --> NH4Cl Homework Equations 1. NaOH + HCl --> NaCl + H2O 2. CH3CO2H + NaOH --> CH3CO2- +Na+ + H2O 3. CH3CO2H + NH3 --> CH3CO2- +NH4+ The Attempt at a Solution I...

Find the set of all solutions of the following differential equation dy/dx=3y I've gotten this far y'=3y y'/y=3 I feel like I'm forgetting a fundamental integration identity like, y=ln(y'/y) <-- Not sure that is even correct. I'm not sure. The book says the solution is...

A Few Tough Physics Problems! I'm stuck, Please Help! 1. Two canoeists in identical canoes exert the same effort paddling and hence maintain the same speed relative to the water. One paddles directly upstream (and moves upstream), whereas the other paddles directly downstream. With...

The draw i keep my kitchen implements in is stuck, i am sure it is the the spatula thing for picking up fried eggs as it has done it before, but this time i can not un wedge it as the draw will only move about 1/4 inch, i have tried shaking, wiggling, pulling, banging it but nothing works this...

Homework Statement http://img375.imageshack.us/my.php?image=70177175xx7.jpg The Attempt at a Solution Hey guys I'm new here and was wondering if i could get some help. I'm stuck on how to construct the matrix A. Any help would be really appreciated!

[b]1. The problem statement, all variables and given integral of : (nRT)/(V-nb)dV from Vi to Vf\int ^{Vf}_{Vi} (nRT)/(V-nb)dV I am really stuck on this one! Do you need to move the denominator up first?

Hey everybody, My professor started our PDE I class in Chapter six, so I am having a hard time with the really basic stuff to get the theory down. One of my questions to answer is to verify a solution by using direct substitution. u(x,t) \ = \ \frac{1}{2}\left[\phi(x+t) \ + \ \phi(x-t)...

Completely stuck with this: \int_0^\infty sin^{2008} x dx Any help on how to tackle this please?

A particle of mass 0.2kg hangs from and ideal spring. In equilibrium, the spring is stretched by amount of 0.49cm. The spring is then suspended from the ceiling of a lift and hangs motionless relative to the lift as the lift descends with a constant velocity of 2.0m/s. The lift then suddenly...

Homework Statement Hey guys. I'm in the middle of this crazy exercise and I got stuck in this ugly integral in the bottom of the page, any ideas on how to solve it? Homework Equations The Attempt at a Solution

two questions that i can't ever remember covering first of all finding a perpendicular vector find a vector perpendicular to the vectors a=i+2j-2k and b=-2i+3j+5k and secondly the equation of a plane?? through point with position vector (2,1,1) and perpendicular to (3,-1,2) what are the...

i have an exam in a few days and am certain a question like this is going to pop up but i have no solutions to this question and no idea how to work it out the question is as follows Find the equations of the line L1 through the point with position vector (4,2,1) and parallel to the vector...

Homework Statement Use trigonometric substitution to evaluate \int{\frac{x^2}{\sqrt{9-x^2}}}dx The Attempt at a Solution Let x=3\sin\theta then dx=3\cos\theta d\theta \int{\frac{x^2}{\sqrt{9-x^2}}}dx =\int{\frac{9\sin^2\theta}{3\sqrt{1-\sin^2\theta}}}\ 3\cos\theta \ d\theta...

Homework Statement Ok, so I need to solve this integral (bottom of the pic) using Stokes' theorem. What I did first is to find the Curl, then I used the UV surface as usual and then found the normal. After that, I switched to an area integral of the dot product between the curl and the...

The cost function for production of a commodity is given below. C(x) = 369 + 21x - 0.08x^2 + 0.0006x^3 Find the actual cost of producing the 101st item. (Round the answer to the nearest cent.) i know that c'(x) = 21-.16x+.0018x^2 but for the life of me cannot figure out how to find...

Homework Statement On a warm day 90F, the air in aballon occupies a volume of .25m3 and exerts a pressure of 20 lb/in2. If the baloon is cooled to 30F in a refrigerator, the pressure drops to 14.2lb/in2. What is the volume of the balloon Homework Equations...

Yet another problem I'm stuck on tonight... The membrane surrounding a living cell consists of an inner and an outer wall that are separated by a small space. Assume that the membrane acts like a parallel plate capacitor in which the effective charge density on the inner and outer walls has a...

I hate it when this happens: Okay, actually I love it when this happens. :smile: This actually happened to me and my teenage daughter several years ago. I couldn't help but yell for help. My daughter wasn't sure whether to die of embarrassment or die of laughter. I think it's worse...