Conceptual Definition and 844 Threads

More conceptual MCQs :) Hi guys, After the concept test that I found quite difficult for some.. apologise for asking so many questions at a go. I try my best to solve for all just hope that any of you would be kind enough to correct any wrongs. I always have the urge to know the correct...

Hi guys I've got a few questions here but I'm unsure whether my answers are correct, although these are the few that I don't have much confidence in. Maybe you guys can help me correct the wrongs. 1) 2 large plates are placed a distance of x apart. The plates are charged to a potential...

concept problem There is a material and it is pulled by a distance by applying a force F. Tell me whether my intuitions is correct 1.In the world around we see materials of different shapes because the inter molecular forces bonds the molecules together in such shapes. 2.If one likes to...

-Ok..Let,s be the Hamiltonian H=H_0 +W in one dimension where W is a "weak" term so we can apply perturbation theory. -The "problem" comes when we need to calculate the eigenvalues and eigenfunction of H0 of course we set the system in an "imaginary potential well of width L" so we have the...

Why isn't time a vector? Hi, I found the following question in Halliday and Resnick's Physics Part I chapter on Vectors and the Laws of Motion. 5.We can order events in time. For example, event b may precede event c but follow event a, giving us a time order of events a, b, c. Hence there...

The wavefunction psi is often separated into two parts, the time dependent part and the part which has only spatial dependence (phi), and this I think can only be done if we assume that the potential is not a function of time. I often see proofs where we have H acting on phi (not psi) and we get...

Hey:smile: , The question: The athlete on the diagram (linked) is free in the air and has a total angular momentum as indiated by the red vector. 1)Indicate with a vector the direction of his twist based on his orientation and angular momentum, show how you got this. 2)Describe 2...

Suppose we have a tube whose cross-sectional area narrows from A_1 to A_2. We attach this to a tank which supplies fluid a constant flow rate Q. Assuming the fluid is nonviscous, we can apply Bernoulli's equation to the narrow and wide ends to calculate the pressure drop \Delta p = p_1 - p_2...

You have just landed on Planet X. You take out a ball of mass , release it from rest from a height of and measure that it takes a time of to reach the ground. You can ignore any force on the ball from the atmosphere of the planet. How much does the ball weigh on the surface of Planet X?

Thank you. Consider a particle moving in a straight line. Does a Large change in speed always lead to a large acceleration? Explain. For a car traveling at a given speed, there is corresponding stopping distance associated with that speed. The stopping distance is the the distance the...

I'm a peer leader for a general physics lab and someone asked me to explain what the Dot Product meant conceptually. I told him it was the projection of A onto B multiplied by the magnitude of B. He looked even more confused after that; my questions are: a) Did I explain it correctly...

I shall give a short example to illustrate where I am confused. If we take the K.E. of a particle in spherical polar coords. T = \frac{1}{2}m( \dot r^2 + r^2 \dot\theta^2 + r^2 sin^2 \theta \dot \phi^2) And T' = \frac{1}{2}( \dot r^2 + r^2 \dot\theta^2 + r^2 sin^2 \theta \dot...

I need to clear some conceptual doubts in the Special theory of relativity. So could anyone explain them in context to the following questions: 1. The speed of light in glass is 2.0 x 108m/s. Does it violate the second postulate of SR in any way? 2. A uniformly moving train passes by a...

When driving on slick roads, why is it advisable to apply the brakes slowly?

amusement park ride...basically a large cylinder rotating about a vertical axis. when it is spinning fast enough the floor is dropped out and the riders stick to the wall well above the floor. find the minimum Vtangential needed. express answer in terms of R of circle, coefficent of static...

i lack the latter, so here is my question, if three objects are shot from a cliff all at different angles...what will their KE be right before they hit the ground relative to each other (neglecting air resistence) now i know the answer to this is they are all equal, having gotten it wrong on...

Hello Im trying to understand light, I did it briefly inhigh school and I am writing the mcat this august... and I am quite confused Is the wavelength of light at a specific frequency in water (n = 1.3) equal to the wavelength in a vacuum / 1.3? Why is violet light not bright? Intensity...

The function y=0 is an equilibrium solution of the natural decay equation and the natural growth equation \frac{dy}{dt}=ky\\k>0. An equilibrium solution is stable if solutions that begin sufficiently close to the equilibrium soltuion tend toward that equilibrium solution as t\rightarrow\infty...

1. Planch's constant[h bar] is really small, so small that in our macroscopic world we generally can't notice it. what if [h bar] were larger, what would our world be like if it were larger? How much larger would it have to be to so that macroscopic objects displayed "quantum behavior'. 2...

Work is the force multiplied by displacement. If i carried my sofa to the moon and back, at the exact same spot. My displacement would be 0, does this mean that i have done no work?

Some straightforward problems I have encountered in QM; i'll post them gradually, otherwise it 'd be a little long, thanks 1a) Wave/particle Duality: A quantum wave as stated through Dirac and von Neumann is a probability wave expressed by Schrödinger equation and thus here implying a...

Q. Can the magnitude of the difference of two vectors be ever be greater than the sum of the magnitudes of the two? Any insights, or answers shall be appreciated... Thanks

What exactly is the finite difference method and difference equations? I know you work backwards, but could you provide some examples? Also how does the finite difference method involve a grid? Thanks

If we have a HCl molecule, then we know that the electronegativity of hydrogen is greater than that of chlorine. So in an electric field, the chlorine will be partially negative and the hydrogen will be partially positive: H: \delta + Cl: \delta - . Then why would this have a dipole moment...

Explain why a point on the rim of a tire has an acceleration when the tire is on a car that is moving at a constant linear velocity :cry: :smile: :mad: :rolleyes: :approve:

A thin rod rotates at a constant angular spped. COnsider the tangential spped of each point on the rod for the case when the axis of rotation is perpendicular to the rod (a) at its center and (b) at one end. Explain for each case whether there are any points on the rod that have the same...

I'm really bad at these because there are multiple answers and I always leave one out. A projectile is fired from a ship at a distant, floating target. Which of the following statements are true? (There can be more than one correct choice.) a. The vertical component of the...

1. ON a distant asteroid, a large catapult is used to "throw" chunks of stone into space. COuld such a device be used as a propulsion system to move the asteroid closer to earth? (need help in terms of momentum,impulse, and all that)

what causes sound waves to travel? is it the pressure, or does sound create a vacuum created by air? Why is it that if you sing at a really high note you can break a glass? Does it have to do something about resonant frequency of the glass? WHy is a pendulum a good basis for a clock? Is...

We know that energy stored in capacitor= \int \frac{q}{C} dq = \frac{q^2}{2C} = qV/2 But work done by battery = qV Where does the other qV/2 go ? Assume NO resistance in circuit The potential of the battery does not change with time

Say a mass is suspended vertically from a spring and is in equilibrium. What is its potential energy? I think its zero because while it has gravitational potential that would allow it to do work downwards, it also has potential energy from the spring upwards. So do these cancel out? It seems...

An engineer wishes to design a curved exit ramp for a toll road in such a way that a car will not have to rely on friction to round the curve without skidding. He does so by banking the road in such a way that the necessary force causing the centripetal acceleration will be supplied by the...

Ok, I don't understand why in a sound resonating pipe, that the in the closed end there needs to be a node and not antinode. Why?

Okay, I guess this is a conceptual problem that I am having with this one. let me explain the problem, firstly: A sedan rolled off the road and needs to be towed. In order to get the car on the tow bed, it is pulled along an incline of 23.1 dgrees with a chain wrapped around a frictionless...

You do no net work when you walk at a constant speed . Why do you get tired? Is the force of a tennis racket acting on a tennis ball a conservative force? A vase falls to the floor and shatters. Is momentum conserved in the collision?What objects needto be taken into account in describing...

I know that Kw is equilibrium constant for water.. but what is Ka and Kb? I Is Ka equilibrium constant for acid and Kb equilibrium constant for Kb? If so how can u find those?? For example..here is an equation Kw = [OH-][H+] = 1e-14 What is the Ka and the Kb? Someone told me that...

Since there are so many possible vacuum states in string theory, with many different possible compactifications and configurations of background D-branes, should (in your opinions) the "final" non-perturbative string theory/M-theory restrict it down to a few or even just one vacuum state or will...

I think I might be confused on some conceptual issues on this problem as I can't really come up with a way to get a numerical answer on anything in this problem. Please help me with any guidance or clarification. The Problem: A square (2.3 cm on each side) wire loop lies 9.0 cm away from a...

Hey guys, just a quick question. If you have a pendulum of length L and a bob of mass M, and if you bring the string to a horizontal position and then give the bob a minimal initial speed enabling the pendulum to make a full turn... the maximum kinetic energy of the pendulum will be when it...

Please don't laugh at the following: I am new to multivariable calculus, and just thought of this on the fly: In single variable calculus, for a function y = f(x) we have the tangent line approximation: \Delta y \approx \frac{df}{dx} \Delta x The relation becomes exact in the limit...

Ok, I'm in a calc based physics course. I'm thinking i should have taken conceptual physics first... we did a problem with the velocity of rain drops hitting a car window. The math i could do ok, but i didn't even semi understand the problem. In my mind the rain was going wicked wicked slow...

Why one past? Quantum theory is very successful in describing bits of matter as clouds (probability distributions). Ironically, it is the proximity of one cloud to another that constrains the shape and size of each cloud. These constraints pile one upon another, ultimately constraining...

I'm having problems with solving these nonconservative forces problems. The teach keeps pointing to Wnc=(KE+PE)f - (KE+PE)i As we use this when there is friction present, I'm totally confused on where the frictional or opposing force is involved when solving. I've basically been ignoring the...

Hi all, hopefully someone can help me out here: I'm looking at the Gibbs' method for orbit determination, and I'm losing the conceptual picture in the vector calculations. I have no problems seeing how D and N point in the W direction (PQW coordinate system), but I'll be damned if I can...