Conceptual Definition and 844 Threads

Ok, First of all, for the formulas torque = r X F If the object is being rotated around an axis parallel to the axis going throught the center of mass, what is the "r" in this case? is it the distance from the axis of rotation to the center of mass? And in what direction would the force...

Homework Statement Just wondering.. does the coefficient of kinetic friction and force of kinetic friction vary with mass? Homework Equations ∑F = mg – Fk = (M + m)a Fk = ukN N = mg uk = [mg – (M + m)a]/Mg The Attempt at a Solution I think that as the mass of an object...

Homework Statement For each of the following statements, determine whether is is correct or incorrect. A. An iron plate has a hole cut in its center. When the plate is heated, the hole gets smaller. B. When the Celsius temperature doubles, the Fahrenheit temperature doubles. C...

Homework Statement True or False Quadrupling the mass will double the period. Tripling the amplitude will sextuple the frequency. Doubling the amplitude will not change the frequency. Halving the amplitude will quadruple the frequency. Doubling the spring constant will halve...

Homework Statement An astronaut is on a space walk when his tether breaks. He has no rocket pack, only a big wrench. How does he get back to the ship? Homework Equations p=mv The Attempt at a Solution I have no idea. I imagined him using the wrench as some sort of "paddle" as he...

So we are working on sound waves in my physics course now and I was doing some textbook reading. I have been following it pretty well, but I just came across a relationship that I am not quite following. It is with reference to wave interference. Let us say that two sound waves are emitted...

One positive (+2q) and two negative (-q) charges are arranged as displayed in figure 1. Calculate electric field E and electric potential P at points along the poitive y-axis as functions of their coordinate y. What is the direction of E at those points? In your results, does y-component Ey...

Homework Statement A small metal cylinder rests on a circular turntable that is rotating at a constant rate. Let R be the distance between the cylinder and the center of the turntable. Now assume that the cylinder is moved to a new location R/2 from the center of the turntable. Which of the...

I am asked to define the phase of a complex function (a wave) in words and physically. I don't know a better way than to draw two different sine functions and show the phase difference on the graph...Any suggestions?

Hi, 1) Can anyone explain to me from a conceptual standpoint, why increased current leads to an increased voltage drop across a resistor? Mathematically, I know V=IR. But it doesn't make sense to me why increasing a current across a resistor would lead to a greater drop in energy per...

Homework Statement 1: An immobile person sees a package falling to the ground. It appears to be falling (a) at an angle, and (b) at speed V1. 2: A pilot flying horizontally at constant speed sees the same package. It appears to be (a) falling vertically, and (b) at speed V2. The...

Hi there :biggrin: I'm having a bit of a conceptual difficulty regarding the equations for inelastic collisions. Suppose a body of mass M1, moving at initial velocity V1, collides and sticks to another body, mass M2, moving at some other initial velocity V2. They then move together with a...

Homework Statement A long straight cylindrical shell has an inner radius Ri and an outer radius Ro. It carries a current i, uniformly distributed over its cross section. A wire is parallel to the cylinder axis, in the hollow region (r < Ri). The magnetic field is zero everywhere outside the...

Homework Statement In Figure 28-28 (see attached), a charged particle enters a uniform magnetic field B with speed v0, moves through a half-circle in time T0, and then leaves the field. Which statements are true? (Select all that apply.) The charge is positive. The charge is...

I was just curious why when doing a taylor series like xe^(-x^3) we must first find the series of e^x then basically work it from there, why can't we instead do it directly by taking the derivatives of xe^(-x^3). But doing it that way doesn't give a working taylor series why is this so?

Homework Statement Does the CM of a system of particles depend on whether the particles are interacting or non-interacting?Will the positon of CM change in another inertial or non-inertial frame? Homework Equations The Attempt at a Solution My attempts:Please check. CM is...

Hey all, I have some hard times with these critical thinking questions. Please help me out. Thanks. 1. The magnitude of the electric field at a point in space does not depend upon... a. The distance from the charge causing the field. b. The sign of the chrge causing the field. c. The...

Homework Statement This is a conceptual question for a lab. In the lab we used two gliders on a nearly frictionless airtrack on a level surface, with photogates set up to measure the velocities of the two gliders before and after the collisions. The second glider was initially stationary...

Let two particles collide. Particle 1 has initial velocity v, directed to the right, and particle 2 is initially stationary. Now assume that the mass of particle 1 is 2m, while the mass of particle 2 remains m. If the collision is elastic, what are the final velocities v1 and v2 of particles 1...

I have both the textbook and the practice book, but only the odd numbered answers are given. I'm trying to do some extra work to better get a handle on the concepts and would like to be able to reference the solutions to check my work. Can anybody help me find a solution set? The book...

I am a beginner in polarization, and questions keep raising when I revise this topic:frown: : Scattering: 1. After the molecule absorb the energy of incident light wave, the energy is reemitted in all direction. Why is it still a kind of polarization if the light emitted is in all...

Questions #1: Will a nail be attracted to either pole of a magnet? Explain what is happening inside the nail when it is placed near the magnet. My answer: Yes, the nail will be attracted to either pole of a magnet because the nail is neutral and has no charge whatsoever. When a magnet is...

Homework Statement Homework Equations I suppose the energy density equation applies here: (P2-P1) + pg(y2-y1) + 1/2p(v2^2 - v1^2) = Epump/vol - IR and I = Av The Attempt at a Solution My initial thought was that the current is the same. But then, since current is Av...

In statistical mechanics, we define \frac{1}{\tau}=\left( \frac{\partial \sigma}{\partial U} \right)_N This formula gives the temperature as a function of the energy of the system and N. So knoweldge of U and N determines the temperature of the system. Conversely, at least when the...

So basically, limits are essential in calculus. When you are taking a derivative, you are basically just taking a limit. I think as a corollary you can say when you are taking an antiderivative or definate integral, you are also taking limits. And the bizarre thing for me, is all the...

I just solved two of Goldstein problems. let me give you the gist. 1. A point mass is on a fixed hemisphere under the influence of a g field. 2. A hoop is on a fixed hemisphere under the influence of a g field. I have found the equations of motion, etc... no probs there. I found that...

I am a beginner in thermodynamics; all I know is how heat is transferred, rotational/translational/vibrational/internal energy, and the law of conservation of energy. I recently learned about specific heat capacity, and I was wondering: why is it that different substances convert varying ratios...

sorry i got one more question, its conceptual and i have a little problem with it, 1. The problem: Bill and Susan are both standing on identical skateboards (with really good ball bearings) initally at rest. Bill weighs three times as much as susan. Bill pushes horizontally on Susan's back...

Hi, 1- In the introduction of the concepts of partition function and canonical ensemble, a system is assumed to be in direct contact with a heat bath (a thermal reservoir) where energy can be transferred between them. All thermodynamical properties of the system can be deduced from the...

Homework Statement The Flux of the E-Field is a vector. It is safer to sit inside a car when lightning strikes than to stand in the open. If the net charge enclosed by a Gaussian Surface is zero, then by Gauss' Law, the E-Field is zero at all points on the surface. The Electric flux through a...

Hi, Any help on this would be appreciated. 1. If you bring a positively charged insulator near one of two metallic spheres that are in contact and then separate the spheres, what charge will the sphere further away from the insulator have? 2. Homework Equations - none 3. I...

A block of mass m is pulled at constant velocity along a rough horizontal floor by an applied force T which is directed at an angle theta above the horizontal. The magnitude of the frictional force is: a. T cos theta b. T sin theta c. 0 d. mu x mg e. mu x mg cos theta I figured it was d...

Homework Statement A car travels at 75 km/h on a level road in the positive direction of an x axis. Each tire has a diameter of 60 cm. Relative to a woman riding in the car, what are the following values? (a) the velocity v at the center of each tire [0 m/s] (b) the velocity v at the...

Conceptual Questions-HELP! Whatcha think of this one? Aqueducts-for our purposes water pipes carried water from the mountains(1000-meters high) to Roman towns. Also common to these towns and connected to the aqueducts-before the water continued into the water distribution pipes of the...

Two people pull on a horizontal spring that is attached to an immovable wall. Then, they detach it from the wall and pull on opposite ends of the horizontal spring. They pull just as hard in each case. In which situation, if either, does the spring stretch more? I think that the spring would...

This is how the book introduced eigenvectors: I do not get how the normal vector of x-y = 0 is <1,-1> . Isn't that saying that the x-component is 1 and the y-component is -1? Also how did they get the vector equation <x,y> = t<1,-1> + <a,b> ? Finally, why does \vec{OQ} = \vec{OP}...

Determine for each of the following statements whether it is always true or can be false. Two objects of different masses but moving at the same velocity have different momentum. -this should be true because p=mv and if there are different v then the p should be different. Kinetic...

What can cause errors in ballistic pendulum lab? Does friction counts in some of these causes?

Here is the problem, it is simple: An air glider is attached to a massless spring, which is compressed 0.18 m from it's relaxed position. Find the velocity of the glider at its original position, and at 0.25 m. Spring constant is 10 N/m, mass of glider is 0.15 kg. I have solved this...

A cylinder rolls up an inclined plane, reaches some height and rolls down (withot slipping throughout these motions). The directions of frictional force acting on the cylinder are : (more than one option may be correct) (a) Up the incline while ascending and down the incline while descending...

I was looking through my book tonight before my midterm exam and came across the following conceptual questions I would like to discuss before I take the test. A rock is thrown straight up. It reaches the top of its path and starts to fall back down. It’s acceleration on the way down...

There are two conceptual questions from last year's exam that I don't know the answer to. 1) From the point of vue of statistical mechanics, why can't we completely neglect the interaction btw particles, even in an ideal gas? My best shot is "Though we can neglect the potential energy btw the...

Hello, I'm a first-year student and I am in advanced calculus (specifically, Analysis I). I, however, switched into the class during the third week. So I am having quite a bit of difficulty, because I haven't learned any fundamental concepts. So I am asking if someone can please discuss a...

If I were to attach a sphere (mass M radius R) to the end of a thin rod (mass m length L), the end of the rod being attached to a pivot, how would I calculate the moment of inertia for that object? The rod: 1/3 mL^2 The sphere: 2/5 MR^2 The object: 1/3 mL^2 +2/5 MR^2 + M(L+R)^2 ...

If you want to show that a system of equations is inconsistent, does the matrix have to be in row-reduced echleon form? For example, I have a matrix which as 0,0,0| 1 as a row. The matrix is not in row-reduced echleon form. So can I still conclude that the system is inconsistent? Or would I...

I am a bit confused, I thought I understood it, but the way the questions are worded seem to suggest I am wrong, which is usually a good indicator... I keep putting things as equal, but it seems a bit of repetitive for everything to be equal. I am using Newton's third law for this. 1...

1) An elevator with a person in it is being pulled upwards by a cable. Identify all interaction forces in the system. Consider your system to consist othe cable, elevator, the Earth and the person. The Earth pulls down on the elevator with force Mg and the elevator pulls up the Earth with...

Here's the question: "An astronnaut working with many tools some distance away from a spacecraft is stranded when the "manueving unit" malfunctions. How can the astronaut return to the spacecraft by sacrificing some of the tools?" I don't quite understand what they're getting at here...

Can someone explain why an absorbance maxium is always used for an assay. What problems would occur if an absorbance minimum were used to get an Absorbance spectrum of a solution? thanks.

I had to miss class today because of a meeting I had with college counselors... please help Hiker (2) is 1000 meters east of hiker (1) when they leave their base camps (@ the same time). Hiker (1) takes the following path: 200 m N, 300 m 30 degrees N of E, 400 m E, 600 m 40 degrees S of W...