# What is homework help: Definition and 28 Discussions

Homework is a set of tasks assigned to students by their teachers to be completed outside the classroom. Common homework assignments may include required reading, a writing or typing project, mathematical exercises to be completed, information to be reviewed before a test, or other skills to be practiced.
The effects of homework are debated. Generally speaking, homework does not improve academic performance among young children. Homework may improve academic skills among older students, especially lower-achieving students. However, homework also creates stress for students and parents, and reduces the amount of time that students can spend in other activities.

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1. ### Help with designing a power generating system

TL;DR Summary: I've been asked to design a power generating system. I could really use some help on how to approach this question, as I cant really find something like that in my study meterial. So I've been asked to design a system that would produce the biggest amount of power possible...
2. ### Find starting velocity from golfer launching ball

Hello! Hope I got this right. Completely new around here. The image that goes along with the problem is: What I have tried so far can be found below: I do not know if it is a computational error or a physics error, but I tried using WolframAlpha to solve for ##v_0## to validate and did not...
3. ### Show that energy E always exists such that junction conditions have a solution

I know this wavefunction should behave as a symmetric cosine function (possibly as Cos( (k∗x)/(hbar) ?). I also know for a bound state, the wavefunction must decay exponentially outside the well. Additionally, r = (-β+ik)/(β−ik) . However, aside from that, I do not know how to get this question...
4. ### Dragging an object: what is Fmin and magnitude of acceleration?

I am not sure how to set this problem up mainly, I am unsure of what equations I need to be using right now. I have tried, for some dumb reason, a multitude of combinations with Cos(39.6) and 124 kg*9.8 m/s^2 as well as one time multiplying the coefficient. I am mainly just struggling with what...

7. ### Constrained motion of a ring along a horizontal rod

The correct answer is u=vcos\theta. I have understood so far to be able to conclude that \text{displacement of string} = PA - PC \approx AB Also, \overline{AB}=\overline{AC}cos\theta or, more generally, \vec{S}_{along\ the\ string}=(\vec{S}_{along\ the\ horizontal})cos\theta Now, I had hoped...
8. ### Electromagnetism: Force on a parabolic wire in uniform magnetic field

I know the easier method/trick to solve this which doesn't require integration. Since parabola is symmetric about x-axis and direction of current flow is opposite, vertical components of force are cancelled and a net effective length of AB may be considered then ##F=2(4)(L_{AB})=32\hat i## I...

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10. ### What is ##Tds## in this equation : ##dU = Tds - PdV##

More explanation : First law is given by ##dU=dQ+dW##. For a reversible change we have: ##dQ = Tds## ##dW = - PdV## So I rewrite first law as : ##dU=Tds - PdV## As mentioned before this ##Tds ## is the heat transferred in a reversible change. And the ##-PdV## is the work done by system in a...
11. ### Help me solve differential equation please involving a fraction and a square root

I'm trying to solve the following differential: ##\frac{\dot x}{\sqrt{y(1+\dot x^2)}} = \text{const}## ##\dot x## is the derivative with respect to ##y##. How do I solve it so that I end up with ##x(y)## solution ? You can find this here, but there're 2 problems: 1) I don't understand what...
12. ### Time period of SHM & Energy conservation in pulley-spring-block system

TL;DR Summary: I was solving this problem given in a book. The answer I got was wrong and seems to violate the conservation of mechanical energy. Yet the forces were balanced. Can someone provide an explanation. So here is the problem: In the above arrangement, I had to find the time period...
13. ### Prove ##(a+b)\cdot c=a\cdot c+b\cdot c## using Peano postulates

I want to prove that ##(a+b)\cdot c=a\cdot c+b\cdot c## using Peano postulates where ##a,b,c \in \mathbb{N}##. The book I am using ("The real numbers and real analysis" by Ethan Bloch ) defines Peano postulates little differently. Following is a set of Peano postulates I am using. (Axiom 1.2.1...
14. ### Find rate at which the liquid level is rising in the problem

I was able to solve it using, ##\dfrac{dV}{dt} = \dfrac{dV}{dh}⋅\dfrac{dh}{dt}## With, ##r = \dfrac{h\sqrt{3}}{3}##, we shall have ##\dfrac{dV}{dh} = \dfrac{πh^2}{3}## Then, ##\dfrac{dh}{dt}= \dfrac{2×3 ×10^{-5}}{π×0.05^2}= 0.00764##m/s My question is can one use the ##\dfrac{dV}{dt} =...
15. ### Engineering Get Expert Help with Your RLC Circuit Design | Easy Step-by-Step Guide

I wrote them on the image
16. ### Chemistry Enthalpy of Formation of ZnO lab

Experiment equation: Zn(s) + 2HCL(aq) -> 2ZnCl(aq) + H2(g) a) If the the mass of zinc solid used was doubled, what effect would this have on temperature change? Answer: if mass of zinc increases, there will be an increase in zinc particles which increases the collisions between particles and...
17. ### Engineering Producing Dry Saturated Steam in a Fire Tube Boiler

Stuck with i & ii can somebody please guide me. none of my coursework material has anything similar in to help me work this one out.
18. ### Equilibrium of Forces and Torques on Sawhorses Supporting a Person on a Board

centre of mass of board at the centre of the board = at distance 6m from left end At no rotation condition and equillibsium IM= net moment of. force = 0 If, = net horizontal force =- ity = net vestical force =0 a. To prevent the board from rotating, the total torque on one side of the pivot...
19. ### Change in reading of the scale when putting ball in a container of alcohol

The container and water inside it are at rest. ##F_{net,y}=ma_y## ##N - (m_{container}+m_{water})g = 0 ## ##N = (m_{container}+m_{water})g## ##m_{container}+m_{water}=700g## ##m_{container}+\rho_{water} V=700g## ##m_{container}+0.8(10*10*8)=700g## ##m_{container}=60g=0.06kg## Now we put a ball...
20. ### Advice needed for producing a water powered car model project

TL;DR Summary: We were tasked to create a water powered car for a project for engineering design and the main specifications is as follows, it must hold 0.7L a min of water. For the first run it must move as far as possible with 0.5L of water and then on the second run it must be able to move...
21. ### What is meant by compex dimension? (Abstract algebra)

picture since the text is a little hard to read i have no problem showing this is a vector space, but what is meant by complex dimention? Is it just the number on independant complex numbers, so n?
22. ### Beam Expansion: Distance between 2 lenses in a Keplerian beam expander

Basically this is the Exercise In Fundamentals of Photonics book. We also need to use these two equation (1) and (2) As we all know, in order to make the z' as far as possible, we must place 2 lens with this distance I already figure that thank to the initial condition of the first lens...
23. ### Solve the given differential equation

I am on differential equations today...refreshing. Ok, this is a pretty easier area to me...just wanted to clarify that the constant may be manipulated i.e dependant on approach. Consider, Ok I have, ##\dfrac{dy}{6y^2}= x dx## on integration, ##-\dfrac{1}{6y} + k = \dfrac{x^2}{2}##...
24. ### Show that the Taylor series for this Lagrangian is the following...

We have ##L(v^2 + 2v\epsilon + \epsilon^2)##. Then, the book proceeds to mention that we need to expand this in powers of ##\epsilon## and then neglect the terms above first order, we obtain: ##L(v^2) + \frac{\partial L}{\partial v^2}2v\epsilon## (This is what I don't get). We know taylor is...

26. ### Speed of cylinder rolling along a horizontal surface gathering snow (Solved)

This is a spin-off of a similar problem posted here in which the cylinder gathers snow as it rolls down an incline. I think one has to understand the snow-gathering process before attempting the more complicated case. A horizontal surface makes that easy but because it is a different problem, I...
27. ### Engineering Calculating the mass of air in a pressurised air tank

Hey folks, any help will be greatly appreciated. I have, what I thought, was a fairly simple equation to follow to determine the mass of air in a pressurised air tank. See below question and my attempt at solving using the pV = (m/Mr)RT) equation. A pressurised air tank supplies compressed air...
28. ### Calculating Average Acceleration of a Particle Moving in a Circle

I was given two HW questions, I was supposed to solve on using ##<\vec{a}> = \frac{\vec{V}_f - \vec{V}_i}{\delta t}## and another using ##<f(x)> = \frac{\int_{x_1}^{x_2}f(x)dx}{x_2 - x_1}##, I was able to solve using the first formula but I wasn't able to do it with second (at least I got the...