Homework Definition and 998 Threads

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...

Homework Statement These two problems are inclined plane problems which I cannot figure out. The problems are attached in the image below. Homework Equations Fnet=ma The Attempt at a Solution I first broke down the gravity force into its x and y components. After that, I did this...

Homework Statement A stationary person observes that rain is falling vertically down at 30km/hr. A cyclist is moving on the level road, at 10km/hr. In which direction the cyclist should hold his umbrella to prevent himself from the rain? 2. The attempt at a solution I used triangle law to...

Homework Statement A small solid sphere of mass M0, of radius R0, and of uniform density ρ0 is placed in a large bowl containing water. It floats and the level of the water in the dish is L. Given the information below, determine the possible effects on the water level L, (R-Rises, F-Falls...

Homework Statement A triangle with a hypotenuse of 13.5 and height of 11.8. Find the measure of angle P. Angle p is on the same line as the 90 degree angle and I found out that it must be sine. Homework Equations sine = opposite/hypotenuse The Attempt at a Solution sin p = 11.8/13.5 sin p =...

Homework Statement Homework EquationsThe Attempt at a Solution my answers are in green, and I have no idea how to complete the last part. What is happening? what does C = c + 4 mean?

Homework Statement Here is the seismogram in question: http://postimg.org/image/iu0dozetn/ There are many parts to this question, but I only need help with this one: Measure the S wave arrival time. Homework Equations NA 3. Attempts at a Solution I know that the P waves arrive at 40...

Homework Statement A loading ramp is 2.8m long. One end rests on a loading dock 0.7 meters above the ground, and the other end leads into the back of a a tractor trailer 1.2m above the ground. Find the horizontal distance between the back of the truck and the loading dock, to the nearest tenth...

Homework Statement he question is: A box is sitting on a board. The coefficient of kinetic friction between the box and the board is 0.4. One side of the board is raised so that the board is 36.8699 degrees from horizontal. This is the angle that the box starts sliding.There are two parts to...

Homework Statement http://imgur.com/a/Yq8pWHomework Equations projection u onto v: ((u x v)/(||v||^2)) x v Unit vector: u/||u|| The Attempt at a Solution For number 2, I absolutely do not know how to set up the problem. I do not know what vectors to use, I assumed F vector to be <0.00375...

Hi, I'm really stuck on this part of my AS biology homework. With reference to theenzymes catalysing the stages of glycolysis, explain how their activity can beaffected. Consider in your discussion if this is a form of intrinsic regulationor extrinsic regulation. 1) Hexokinase: 2)...

I have been studying the method of symmetry from some days, which essentially reduce the effort needed for the evaluation of equivalent resistances. My textbook states: Points having symmetrically located about initial and final points have the same potentials.So, the resistances between these...

Homework Statement The following function is periodic between -π and π: f(x) = |x| Find the Coefficients of the Fourier series and, by examining the Fourier series at x=π or otherwise, determine: 1 + 1/32 + 1/52 + 1/72 ... = Σ∞j=1 1/(2j - 1)2 Homework Equations f(x) = a0/2 + ∑∞n=1 ancos(nx) +...

Homework Statement the answer that i get is different with the answer provided , is my answer wrong ? i got ( cos(2n -1) / 2n-1 )instead of ( cos(n+1) / n+1 ) Homework EquationsThe Attempt at a Solution [/B]

Homework Statement Homework Equations 1/do+1/di=1/f The Attempt at a Solution I tried finding the distance of image at 27m and then at 30.5m and taking the difference but that didn't work.

Homework Statement Show that the following is NOT a vector space: {(a, 1) | a, b, c, ∈ ℝ} {(b, c) Note: this is is meant to be a 2x2 matrix. This may not have been clear in how I formatted it. 2. The attempt at a solution I am self-studying linear algebra, and have had a difficulty...

Homework Statement Suppose we drop a lead ball of mass M into water of mass m from a height h and allow everything to settle down. What is the temperature change of the water? Assume that the container is well insulated. Homework Equations Potential Energy = mgh dU = mcdT where dU is the...

Homework Statement The electric potential a distance r from a point charge q is 195 V, and the magnitude of the electric field is 2870 N/C. Find the values of q and r.Homework Equations 2780q=F Fr=W W/q=195 The Attempt at a Solution Using substitution I got r=.00679 meters, which is correct. I...

Homework Statement is the author wrong ? i was told that the f(x) = 0.5(a_0) +Σ(a_n)cos (nπx / L ) ... but , in the example(photo2) , the author ignore the L , which the author gave f(x) = 0.5(a_0) +Σ(a_n)cos (nπx ) +... Homework EquationsThe Attempt at a Solution P/ s : i have tried to make...

Homework Statement A current 2A flows in a wire. Value of horizontal component of Earth magnetic field in the region is 2x10^-5T. Small compass placed 5cm due north of the wire. Calculate the angle through which the needle deflects due to the current flowing in the wire. Assume u0= 4pi x 10^-7...

Homework Statement Homework Equations relevant equations listed with each question The Attempt at a Solution a) to solve for the power output of the heater, i used the following equation: Power = Energy/time i already know that Energy = Quantity so based on this, i can solve for Q = mass(ice)...

Homework Statement A block and a spool are each pulled across a level, frictionless surface by a string. The string wrapped around the spool will unwind as it is pulled. Both the block and the spool have the same mass and are pulled with the same constant tension. Which will cross the finish...

Homework Statement Find i and v_x Given answer: 2. Homework Equations 3. The Attempt at a Solution I have attempted the problem in two different manners, and I consistently reach a different answer. I would appreciate if someone would be willing to take the time to attempt the problem and...

The question asks: Uranium nuclei are unstable and decay by emitting a helium nucleus, which contains two protons and two neutrons. Suppose the original nucleus has 92 protons and 146 neutrons before it emits the helium nucleus, and that the helium nucleus has an knknown speed as it departs from...

In my electrical engineering textbook, in the section with voltage dividers, it says that after you combine two series resistors, then the output voltage can no longer be defined. It then said that thus the equivalence was made strictly from a voltage source standpoint. I do not understand why...

Homework Statement why the Q1 for AB is 5 ? for Ac is -5 , while for CB is -2 ? how to determine them ? I could only see Qat A = 10.0 , Q at C = 3 , Q at B = 7 P/ s: the author take clockiwse direction to be positive , anticlockwise direction to be negative ... Homework EquationsThe Attempt...

Hi all, I have this question in my HND... A hydraulic jack has a load piston diameter of 150mm and a plunger diameter of 25mm. a) Ignoring losses, calculate the force required on the plunger to raise a load of 2500Kg. I have calculated my answer (correct or not i don't know) to be...

Hello, I didn't know if this is the right place for this question but here it is. I have a thesis due by June sometime. The thesis is in an astronomy course so I would like to do something on physics. I have just started learning the basics and would like to impress the teacher (this might help...

Homework Statement Two long parallel horizontal rails, a distance d apart and each having a resistance λ per unit length, are joined at one end by a resistance R. A perfectly conducting rod MN of mass m is free to slide along the rails without friction (see the figure). There is a uniform...

Homework Statement Two canoeists, A and B, live on opposite shores of a 300.0 m wide river that flows east at 0.80 m/s. A lives on the north shore and B lives on the south shore. They both set out to visit a mutual friend X who lives on the north shore at a point 200.0 m upstream from A and...

Homework Statement The distance between cities A and B it's L. An airplane flies back and forth between A and B, in a straight line, with velocity V in relation to the wind. So, calculate the total time of the flight, if the wind blows with velocity v, in a direction which forms an angle theta...

Homework Statement You have been given a milkshake (ρ = 1200kg/m^3). The glass is 200mm tall a straw 8mm diameter and 300mm long. Show that human lungs would be unable to drink the milkshake through a vertical straw. (answer should be around 3000Pa) I have no idea what to do as I don't know...

Homework Statement [/B] The two blocks are moving rightward at a constant speed along their inclined surfaces. The coefficient of kinetic friction is the same for both blocks. a) Determine the coefficient of kinetic friction. b) Determine the tension in the cord that connects the blocks to one...

Hello everyone! I have a (supposedly) calculus problem that I just can't seem to figure out. Basically, I'm trying to understand why alternative kinetic energy formulation does not yield the same equations of motion in problem 11 of Goldstein's Classic Mechanics 3 edition. The text of problem...

Homework Statement A small package is placed on the platform of a non-rotating merry-go-round, 2.72 m from the vertical rotation axis. At t=0, the merry go round begins rotating with a constant angular acceleration of α = 0.100 rad/s^2. The coefficient of static friction is 0.600. Determine the...

Homework Statement A little stuck on the second question it basically boils down to not quite understanding the question. Was hoping someone here could push me in the right direction. The Question is two part, already completed the first half but wouldn't mind if someone looked over it while...

2 = X to the power x to the power x, until infinity. I really need to know how its possible for the answer to be √2

Homework Statement Uncharged metal plate area S and thickness d located at a distance r from the point charge q and oriented perpendicular to the vector r, as shown below. Find the electric force between the plate and the charge. The plate thickness is less, and the distance r is much greater...

Homework Statement A proton is moving at speed v from infinity toward a second stationary proton, as shown below. Determine the minimal distance between them. http://s27.postimg.org/lmw3d21j7/Untitled.png Homework Equations W = \frac{kq_1q_2}{r} E_k = \frac{mv^2}{2} The Attempt at a...

Homework Statement How do you find the position of a pendulum as a function of time? Mass of bob: 2.0kg String length (l): 3.0m The pendulum is displaced as a distance of 0.35m from the equilibrium point and is then released. After 100 swings the maximum displacement of the pendulum has been...

Imagine an 8x8 chess board. In how many ways can 8 queens be placed on the board such that no queen can "eat" any other queen.

Twenty per cent (20%) of a rubber ball is floating above the surface of a pool of water. If water has a density of 1000 kg/m^3 and the ball has a mass of 3 kilograms, what is the volume of the ball?

Homework Statement You are traveling on an airplane. The velocity of the plane with respect to the air is 160 m/s due east. The velocity of the air with respect to the ground is 41 m/s at an angle of 30° west of due north. 1) What is the speed of the plane with respect to the ground? Homework...

hi I don't understand how to do one type of homework problem, here's an example of the type: If limit of f(X)/X = 1 as X ->0 evaluate the limit f(X) as X->0

I ran into some problems when trying to finish my assignment. The objective of this assignment is to create a block of code that will keep asking the user to input numbers until the input is 0. And if the user input 0 for the first value it will say "No data submitted!". I got all those parts...

I need to give a presentation about roger bacon (the guy who said that rainbows form at a 42 degree angle). It's hard to find information about his study of rainbows so if anyone knows something about it I'll be grateful.

Homework Statement First question = attached below Second Question = attached below Homework Equations modulus, argument, roots. The Attempt at a Solution For the 1st question I've gotten the modulus, the principal argument and the abs. of z^1/4 which was something like 1.5335 I believe. The...

Homework Statement A block of mass m slides down a frictionless ramp from height h above the floor. At the base of the ramp it collides and sticks to the lower end of a uniform rod, length L, mass 2m, that is suspended about a pivot at point O, about which it is free to rotate. Express...

Homework Statement Homework Equations Refer to 3. The Attempt at a Solution My problem is the theory I am unsure how any equations apply to this problem. This seems bad that I have no attempt at solution but I am honestly unsure how to start or of any relevant equations.