Homework Definition and 998 Threads

Homework Statement A slab of dielectric of thickness a and relative permittivity ε is placed in a uniform external field E whose field lines make angle θ with normals to the surface of the slab. What is the density of polarization charge on the surface of the slab? Neglect end effects...

Homework Statement http://i.imgur.com/wSvUEU2.png Homework Equations (written in the photo) The Attempt at a Solution (written in the photo) Thanks

Homework Statement See Image The bit about Spectral lines, I couldn't explain why[/B] Homework Equations ΔEΔt≈h The Attempt at a Solution I expected the histogram to peak at the given mass in question and to have a width of about 0.08 MeV calculated as ΔE from the Energy-time uncertainty...

Homework Statement I encountred a question that says : Assume that gravitational interactions between galaxies in groups lead to random galaxy velocities of 300 km/s At what distance would the redshift predicted by Hubble's law dominate over that produced by individual velocities? and what is...

Homework Statement What is the value of V2 in terms of Vos? Homework EquationsThe Attempt at a Solution In the class, we were told that this is just a non-inverting amplifier, thus V2= Vos x (R2/R1+R2). However, I want to work out the solution by applying nullator hypothesis (voltage...

Problem: Consider a 360-nm thick oil film floating on the surface of the water. The indices of refraction of the oil and water are 1.5 and 1.33. The surface of the oil is illuminated from above at normal incidence with white light. (A) Find the shortest wavelength of light in the 400nm to 800 nm...

Homework Statement Imagine that you are standing on the edge of a cliff looking out over the vista… a sudden gust of wind nudges you off balance and you start tilting out over the edge of the cliff…. Yikes! You start wind milling your arms to regain your balance. A) do you rotate your arms...

Homework Statement #include <stdio.h> #include <stdbool.h> #define MAX_STRING 256 #define MAX_LINHA 1024 typedef struct{ int dia, mes, ano; }Data; int contar_linhas(char fname[]) { FILE *f; Data int soma=0; // Inicializa o contador f =...

Homework Statement The 5.7 N weight is in equilibrium under the influence of the three forces acting on it. The F force acts from above on the left at an angle of α with the horizontal. The 5.2 N force acts from above on the right at an angle of 63◦ with the horizontal. The force 5.7 N acts...

Homework Statement A box of mass 6.2 kg slides 4.8 m down a ramp that is inclined 38 degrees to the horizontal. What is the velocity of the box right before it hits the ground? Mass=6.2 Height=dsintheta? V=is what needs to be found theta=38 Homework Equations GPE=mgh=mgdsin(theta) KE=1/2mv^2...

We were writting a test on wednessday and for the first question we were asked to calculate the angles of the base of a tetrahedron with points A,B,C,D. ABC being its base. We were also given some relation which helped me calculate that the base of the tetrahedron is an equilateral triangle...

For my physics assignment we have to design and test a way to allow an egg to fall from a three storey building and not crack. The only requirments are the egg must be visible in atleast one place and the smallest design wins. I tried making a crumple area and then protecting the egg with...

Homework Statement A certain circuit has a resistance of 30 Ω, inductance of 5.0 mH, and capacitance of 0.375 µF. At time t=0, the capacitor is charged with 4.0 µC on the top plate (and -4.0 µC on the bottom), and the switch is then thrown so that the capacitor can discharge through the...

Can someone please help me out with this tough problem? 1. Homework Statement A ball rolls on a turntable without slipping describe the balls motion in terms of (x,y) for a function of time. (The turntable spins at a constant rate) (This all the information that the professor gave us.)The...

Homework Statement If an object had been projected horizontally with the same magnitude as in the depicted situation, how would the motion compare with that of the object in the diagram? (I have drawn the diagram in my attachment and have done questions c and d but I don't understand question...

Homework Statement [/B] The diagram shows a thin rod of uniform mass distribution pivoted about one end by a pin passing through that point. The mass of the rod is 0.380 kg and its length is 2.50 m. When the rod is released from its horizontal position, it swings down to the vertical position...

Homework Statement Sulfur hexafluoride is a centrosymmetric molecule with four infrared inactive vibrational modes: 346 cm-1 , 524 cm-1 , 643 cm-1 and 775 cm-1 The Raman spectrum of a liquid sample of SF6 (held at elevated pressures) was measured with a laser that has a centre frequency of...

Homework Statement Homework Equations Torque and Newton's 2nd Law Equations The Attempt at a Solution Apart from drawing a free-body diagram, I couldn't do much else. I can't seem to find the source of torque causing the car to rotate clockwise about its pivot (i defined it as the right...

Homework Statement A long solenoid has a radius of 3 cm, 3000 turn per meter, and carries a current I = IOcos(ωt), where Io is 0.25 A and ω is 628 s−1 . It is placed through a circular loop of wire, radius 5 cm, which has resistance 100 Ω. The magnetic field in a solenoid is B = µonI. (a) Find...

I was wondering if there were any good online resources for AP Physics C with notes, practice tests, etc.

Homework Statement (2) Suppose a particle of mass m is subjected to a repulsive force F = +kx. (a) What is the general solution for the motion of the system? (b) If the particle begins with a position x(0) = x0 and with velocity v(0) = v0 at t = 0 what are the values of the constants appearing...

In the (b),I have some questions: (1) Does it mean ψ can be real or not real? (2) Why do the solutions of linear combination must have the same energy? As I know, these solutions are often different, as long as they are eigenvalues of time-independent Schrodinger equation. (3) In the sentence...

Homework Statement An 8kg object is moving in the positive direction of an x axis. When it passes through x=0, a constant force directed along the axis begins to act on it. The figure gives it's kinetic energy K versus position z as it moves from x=00 to x=5.0 ; K(initial)= 30 . The forces...

Homework Statement A.) Distance, the length of which is 350km, was done within 4 hours. Some part of the distance was driven at speed of 60km/h, and some part of the distance was drivent at speed 100km/h. What part of the distance was driven at 60km/h speed B.) How many students were at the...

Homework Statement The coefficient of static and kinetic friction is constant for a specific surface. On an incline plane s and k are both equal to tan of the inclined angle. If the angle increases then tan changes which means the coefficient of friction changes. How is this so? Homework...

Homework Statement A bead slides on a wire, which is in a vertical plane, as shown in the diagram. Gravity acts in the -y direction. The bead starts at A, moving to the right with an initial velocity v. The wire is frictionless between A and D and between F and G, but there is friction between...

Homework Statement A ball of mass m falls from height hi to height hf near the surface of the Earth. When the ball passes hf, it has a speed of vf. Ignore air resistance. Consider the system T which consists of the ball only. Write an expression for each of the following quantities in terms of...

An ideal gas at initial state has temperature 300 K has been compressed under constant pressure of 30 Pa from volume 3 cubic meters to 1.8 cubic meters. In the process 75 J of heat was lost. A. Find the change in internal energy B. Find the final temperature I tried two methods in A and they...

Homework Statement Homework Equations ∫ F dt = mv The Attempt at a Solution I have ∫ T -mg dt = ∫ 100+2t2 - mg dt = ∫ 100-9000*9.81 +2t2 dt but then I got negative impulse ...??

Homework Statement A speed skater increases his speed from 10 m/s to 12.5 m/s over a period of 3 seconds while coming out of a curve of 20 m radius. a. What is the magnitude of his angular velocity as he leaves the curve? Be sure to include proper units for your answer. b. What is his average...

Hi, I'm new here so I'll make it quick, we have just finished studying mechanical waves so I need some homeworks to share with my classmates. We have done the basic ones so we want to move to solving complicated problems surrounding: Wavelength, velocity, frequencies and diffraction.

Can anyone recommend published homework sets even without solutions for an intro to waves/optics course, the 3rd of a typical 3-course intro physics sequence? I had been following MIT's intro sequence (8.01, 8,02, 8.03) while taking a course that follows Halliday/Resnick, which I do not find...

I am wondering if this is an appropriate place to ask people to check my homework answers? I am willing to type up the problems and my answers to see if they are right and to get additional suggestions, I just want to make sure this is a place I can do that. If it's not, does anyone know of a...

Homework Statement I have to find the matrix system of Sx, Sy , and Sz using the given information: 190899[/ATTACH]'] Homework EquationsThe Attempt at a Solution for attempting Sx: Ignoring the ket at the bottom, I would get Sx|+> = +ħ/2[[0,1],[1,0]] but my question here is, does the ket at...

Homework Statement On a farm, you are pushing on a stubborn pig with a constant horizontal force with magnitude 34.1 N and direction 37.0∘counterclockwise from the +x-axis. a) How much work does this force do during a displacement of the pig that is s⃗ =(5.00m)ι^? b) How much work does this...

Homework Statement A highway is to be built between two towns, one of which lies 35.0km south and 72.0km west of the other. What is the shortest length of highway that can be built between the two towns, and at what angle would this highway be directed with respect to due west. Homework...

Homework Statement Specific Activity of a sample of rubidium chloride is 478 Bq per gram knowing that activity is coming from Rb-87, calculate the half life of radioisotope - Molar mass of the RbCl natural is 120.9256 gram - Isotope composition of natural Rb is 72.15% and 27.85% respectively...

Homework Statement In the Atwood’s machine, what should M be, in terms of m1 and m2, so that it doesn’t move? Homework Equations F=ma The Attempt at a Solution I've set T1=Mg as T1 is the tension of the rope attached to M. m1 and m2 are both connected together by the same rope so I assumed...

Homework Statement You go to an amusement park with your friend Betty, who wants to ride the 90-m-diameter Ferris wheel. She starts the ride at the lowest point of a wheel that, as you face it, rotates counterclockwise. What is the magnitude of her displacement vector when the wheel has...

Hello everyone I couldn't figure it out a simple way to solve 15. 11 C . Please help ! Very appreciated!

<Moderator note: moved from technical forums, so no template> Problem: Two trains (A and B) are moving along parallel tracks at different speeds. A person sitting on train A looks out the window and sees two things happen: a firecracker explodes right outside his window, and, exactly 1.0...

Homework Statement Homework EquationsHEAT PRODUCED=WORK DONE BY BATTERIES - ENERGY ABSORBED BY CAPACITORS The Attempt at a Solution INITIALLY BEFORE SWITCH CLOSED :Initially a current flows only in the left most loop involving 4 microfarad capacitor.The charged on the capacitor during...

Homework Statement Hey Guys, I don't really want to have to post this in of all places due to how advanced everyone else is compared to me, but I went to my second physics class and I have a huge problem. My teacher gave me my homework, but I have no idea on Earth how to do it because she...

Homework Statement I got the problem down to: \frac{2}{\pi} \left[ \int_{0}^{\pi/2} \frac{2}{\pi}xsin(nx) dx + \int_{\frac{\pi}{2}}^{\pi} (\frac{-2}{\pi}x+2)sin(nx) dx \right] \frac{4}{\pi^2} \left[ \int_{0}^{\pi/2} xsin(nx) dx + \int_{pi/2}^{\pi} -xsin(nx) dx + \int_{pi/2}^{\pi} \pi...

Homework Statement Homework Equations F=m*a ΣF(n-direction)= m*a(n)= m*(v^2/ρ) ∑F(t-direction)= m*a(t)\ Ffriction= Fn*coefficient(of friction) The Attempt at a Solution So I tried solving this question and apperently it is way easier than I thought. So I thought the kinetic friction has a...

Homework Statement Homework Equations f=m*a V= Vg*cos θ The Attempt at a Solution Is this solution correct. I did everything the same, but I did not use the 15 ft/s. Since An= (v^2/ρ) with V being the velocity in the t direction. The 15 ft/s according to me is only the component of V that...

Homework Statement Homework Equations F=m*a The Attempt at a Solution Don't worry it not a homework question of mine. I was just trying to solve some questions (on my own) that I know I have difficulty with to get better at it. Especially with springs I can get confused, so I thought I...

Homework Statement Hydrolysis of ethyl lactate Determine the value of the rate constant for the hydrolysis of ethyl lactate from the following data. Mass of ethyl lactate (grams): 0.5956 Concentration of stock HCl solution (M): 0.01023 Standardization titration volumes (of NaOH): Run...

Question : Find the electric field at the centre of a ball of radius R with volume charge density rho = a.r, where a is a constant vector and r is a radius vector drawn from ball's centre. Relevant Equations and attempt at solution : I used the basic formula for electric field due to...

Homework Statement This problem asks for the angle on an inclined plane-- I have attached the problem below. Homework Equations fnet=ma The Attempt at a Solution I honestly have no idea what to do. I found the vector components for gravity and made a FBD for the box, but I can't really figure...