Homework Definition and 998 Threads

Burning waste in a waste-to-energy plat, can more energy be produced by burning the trash then the amount of energy needed to heat the trash to the point it vaporises? (to turn it to ash) eg we have 100 J of energy inside some rubbish, and this energy would all be released when we incinerate the...

Summary:: Hi anyone can explain me how to solve this circuit, finding the current I2 and I1? Really don't know where to start Thanks

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Hello, Can someone explain how to sketch the flow profile in detail. Also, I solved for curl, but I'm getting a zero while the answer is the differentiation of the function f(y). Pls do help me out!

I would really appreciate if someone helped me do this homework, btw it's in french

Sorry for the bad english. This might sound stupid but I am pretty new the physics and i can't seem to find what formula to use on this problem when only the mass, gravity and height of the fall is given. and i can't find a similar problem in the book, could someone give me any pointers? Thanks...

I got this as homework and I am not sure how to attempt it

Hello, any answers appreciated: 'Two spheres are 5 m apart. Sphere 1 has a charge of -20 mC and sphere two has a charge of -50 mC. (a) Find the strength of the electric field at the sphere's halfway point. (b) Find the electric potential at the halfway point

We know that ##v = \omega r## where ##r = R_{\text{E}} + h##. To compensate for the motion, the plane must fly along the equator at the same speed as the Earth but in the opposite direction, i.e. from east to west, so $$\vec{v} = -\vec{ v}_{\text{E}}$$ $$v_{\text{E}} = \omega_{\text{E}}...

I have no clue. The answer is the stretched one but i don't know why.

I need help actually creating the proof. I've done the scratch needed for the problem, it's just forming the proof that I need help in. Bar(a+bi/c+di)= (a-bi) / (c-di) Bar ((a+bi/c+di)*(c-di/c-di)) = ((a-bi/c-di)*(c+di/c+di)) Bar((ac+bd/c^2 +d^2)+(i(bc-ad)/c^2+d^2)) =...

I have tried this problem over 4 times and keep getting the exact same answer, which is incorrect. Could someone please help by pointing out what I did wrong, or letting me know if I am actually on the completely wrong path? Thanks! Have a wonderful day :)

I'm not looking for someone to tell me the answer, just help steer me in the right direction. I feel like I need to find the air density or air velocity at entry to proceed, but I'm unsure any help and guidance is greatly apricated!

(I accidentally missed my lesson and I don't know how to apply this question to the formula)

Unfortunately, there's no formula i know about, so i have no idea how to solve this... Hope you can help me out... Greetings

Summary:: Tripped by my grand daughter's math homework again! This is the homework of my grand daughter, I don't understand the question: I wrote the questions in red. I have not done geometry for a long time! I don't understand the equation JM^2 = KM . LM. Is the "dot" just multiply? or is...

How exactly would it then be calculated? Here's what I have tried: proton mass: 1.007276 amu Neutron mass: 1.008665 amu Sulphur-34 mass: 33.9678668 amu Calculation: 1.##(16\cdot1.007276)+(18\cdot1.008665)+(16 \cdot0.000549)=34.28117## 2.##34.28117-33.9678668=0.3133032## 3. 1 atomic mass...

Answer B would increase the n1/n2 ratio and increase the deflection. Making it correct. But also, Answer A would increase the current through the primary coil, and hence the power. This would increase the power in the secondary coil hence I2, leading to lower voltage V2. Making it also correct...

The paper is https://core.ac.uk/display/10365043 (12MB pdf) My purpose is to construct parametised spiral bevel gears (using OpenSCAD). I know how to produce a correctly formed circular cut (cylindrical) crown gear profile. My problem is mapping that to a conical surface. I am looking for...

Points A b AND C are shown in first diagram Im confused about question three... I feel like its related to wave length but the fractions are throwing me off.

For this problem I know how to get the answers but I have a few things I’m not 100% sure about. First how do we know that the rod is experiencing centripetal motion? Second, when using moment about point G how do we know that the angular acceleration is equal to zero? And third the radius is 0.4...

So for this question, when using point B as the centre of the moment, I get different sign for the mad term. If you take clockwise as positive than 100N force and the force at point G are causing a positive moment and gravity is causing an negative moment. But the solutions have different signs...

So I’m confused about a few things in the solution. Why is it that speed of the V_h appears on both gear a and b? Is it because both gears are both in contact so they have equal speeds just in opposite direction. Same confusion for V_e being on the top of gear b. So Just because gear e doesn’t...

So I've just learned Norton's Theorem and I have this problem on my homework assignment that is wrong. I've checked the answer with a circuit simulator(PSPICE) and the simulation said that V0 should be a drop of 2V. However, my simplified circuit shows a voltage drop of 4V. I have been staring...

I tried following the formula but it wasn’t correct. I’m sure I could get it if I had an example as I’m sure this must be a simple question for other people I was just unsure if I was doing it correct.

March 21 - October 21 = 7 months. So the star is only 15m 39,3 seconds behind the sun. This means that the star won't be up when the sun is down. Answer: No, the star will set only 15 minutes after the sun has set. Therefore it won't be on the sky at the specified latitude during dark hours...

1. Keplers third law (and the asumption that M1+M2 ~ M1) gives that M_Mars = 4*Pi^2*a^3/(G*T^2) With numerical values inserted Mmars = 4*3.14^2*(9400*1000+3396.97*1000)^3/((6.67*10^-11*(7*60*60+39*60)^2) 2. Phobos needs 7h39 minutes to complete a circle, this gives a speed of...

ψ(y,t)= -2A sinky sin wt Why is this called a standing wave?

I arranged the masses in ascending order: 11.0 g 11.1 g 20.6 g 21.4 g 21.5 g 25.7 g 25.8 g 25.9 g 31.6 g 31.9 g I found the average mass of the marbles: 22.65 g I found the difference in masses of the marbles: 0.1 g 9.5 g 0.8 g 0.1 g 4.2 g 0.1 g 0.1 g 5.7 g 0.3 g I found the average of the...

For a) I did Eg = Ee + Eg and tried to solve for x. I got 5.4 m but I think this is wrong. I have no idea how to do the rest, please help :')

Hey, I am new to this community and I am in need of help with this physics problem. I have used the formula above and the answer I get is 1.43s. The correct two answers are 0.68s and 2.4s. For the Vf the answer is 8.3 m/s.

150 km tan(35)=150/x Hyp=316.58 I know this isn't right where did I go wrong or did I even start correctly

the answer in the solution book is 29K which only comes if I use mass for only one atom. ( They did not show any working ) My attempt: 1/2 x (1.67 x 10^(-27)) x (355)^(2) = 3/2 x 1.38 x 10^(-23) x T T = 29.48820652 K The confusion arises when I tried the following question: Q. Estimate the...

I solved this with two methods as you can see down below in the picture. Which is the correct way? I remember I learned in class you could use both ways but why am I getting different results?

Summary:: Not sure how to My question is what is h2o , because ts is for example : 48,25 and what is ps . Is h20 the 0,99708? 48,25

Below I've attached the question - I don't know why this question is so difficult, perhaps I missed a lesson or such, however I've Benn working at it for ages and got nowhere...

From the solution of my thermodynamics homework, $$ ({\frac{\partial h_{fg}/T}{\partial T}})_P \\ = ({\frac{\partial h_{g}/T}{\partial T}})_P - ({\frac{\partial h_{f}/T}{\partial T}})_P = \frac{1}{T} ({\frac{\partial h_{g}}{\partial T}})_P - \frac {h_g}{T^2} - \frac{1}{T} ({\frac{\partial...

For question A, I know that I am supposed to input the numbers given into the Universal Gravitation Equation, but I do not know how to solve for it beyond that. For question B, I know that the astronauts weight depends on the mass and gravity of the new planet but I do not know how to prove it...

Homework Equations Conservation of energy. Kinetic energy=(1/2)mv^2 The Attempt at a solution m=1.5*10^3kg, final velocity=25m/s, initial velocity= 11m/s, distance=0.20 and work done=? What do I do next.

My attempt so far: I put all the terms to become smaller than zero: so ##x<-4## becomes ##x-4<0## ##-1\leq x\leq 3## becomes ##-1-x\leq 0## and ##x-3 \leq 0## ##x>6## becomes ##x-6>0## which is the same as ##-x+6<0## (i think)... I am now stuck on making it a rational inequality... anyone...

Please someone help me

Here's a diagram of the object My Question: My friend and I were solving this problem. We both found Fxnet and Fynet. However to find work I did W= Fnet*d whereas he did W= Fxnet* d. He claims that since it's sliding on the floor it can only go in the x-direction, and it can't go in the...

It was a long time ago I did these kind of problems so I’m a bit rusty. The only thing I can think of is divide it up to two parts one x and one y. In y the acceleration is sin(a)*9.82? Then put that in the equation and solve for t. In x the there is no acceleration so the formula is x=V0*t, I...

Look on picture two for my equations, I’m pretty sure my first three equations are correct as it’s the same on the answer paper I got. Answer paper only shows the three equations and correct answer so I have no idea how they got to it. When I put the equations togheter And solve out ”h” i get...

I assumed that the vertical force at point B would be the same as the force between beam CB and E because of Newtons law. Did I assume wrong? Look below for my calculations and answer which I got to 250N. I don’t know the correct answer but assume someone here can tell me if I solved the problem...

Edit: So I have written out equation 3 again and taken a picture to show my working out, the 2 things that I am confused about is how do I find the coefficient of viscosity? I know that syrup is high viscosity and water is low viscosity but I don't know the equation to get the actual value. The...

if the ends P and Q are being pulled down with a uniform speed its acceleration is zero and hence the Tension in the string will also be zero and if this is the case which force will make the block of mass M rise? is this a fatal flaw in the question?

I don't know how to start doing this homework. I would like help to orient myself.

1a) Step 1: Balance the equation - S8 + O2 -> SO2 = S8 + 8O2 -> 8SO2 Conversion (t to g) 6.00 t = 6x10^6 g Molar mass SO2 = 23 + (2 x 16) = 64 g/mol 6x10^6 g / 64 g/mol = 9.375x10^4 mol SO2 reqired amount Sulphur = 9.375x10^4 mol / 8 mol = 1.172x10^4 mol S8 Molar mass S8 = (8 x 32)...

Hey guys! I´m having a lot of trouble , even on starting this problem. Can someone give me a help?? [Moderator's note: Moved from a technical forum and thus no template.]