Law Definition and 999 Threads

Hi everyone, Someone posted this hypothetical problem on a facebook group and I am wondering what your thoughts are. The issue is that Snell's law does not seem to hold when applied to the transmitted wave (calculated using the electromagnetic interface conditions.) Here is an example...

Hubble's Law and Star Velocity By using Hubble's law and the principle of velocity superposition of relativity, we can deduce when the distance of star from the observation point is (photometric distance)r, its velocity V can be expressed as: V = Csin (Hr/C) Therefore, the...

$\tiny{18.3.6 Coulomb's Law }$ $\text{A charge of $q_1=4.0 \mu \, C$ is at origin, and charge}$ $\text{$q_2=6.0 \mu \, C$ is on the x-axis at $x=3.0 m$ }$, $\text{(a) find the force on the charge $q_2$ } $ $\text{(b) find the force on $q_1$ } $ $\text{(c) how would your answer for parts (a)...

Hi all, I have attached an image of a page out of the book I am using for context. The blue arrow in Figure 12-3 describes the motion of the particle. I figured the net force would need to be in the same direction, but apparently the net force opposes the motion. So, in Figure 12-3 the pressure...

Answer: (a) Attempt: In Metaphase I, homologous chromosomes separate. Out of the four options, dig (a) and (d) have correct representation of separating homologous chromosomes. Now, according to the law of independent assortment, during segregation the chromosomes can group in any combination...

2 bodies that have distance d between them are distancing from each other because Hubbles law. at time t=0 distance between them was d(0) and speed between them was 0. If no force interacts with them then distance is increasing by rate ##\frac{\partial d}{\partial t}=H_0*d## Is it correct...

Problem Statement: Please help me understand the variables for the equation, 5 log(R) = -m + k. Relevant Equations: 5 log(R) = -m + k Here is the link to where I found the equation. I know it's on wikipedia but I checked the Hubble's paper and it seems to be credible. I'm trying to make...

The motor is required to operate at its resonance frequency and I am looking to add a thin-walled (0.010") copper tube inside the stator bore to add some damping. The current motor air-gap is 0.015". If I install a copper tube in the stator bore bonded to the stator and leave a 0.005" air-gap...

Sorry there, relatively new to this topic. Anyways, from my understanding of the formula, the force is equal to mass times acceleration. So, is it safe to assume that the total force is simply all the forces from the engines added up? (1.7MN^3+23MN^2), while the mass is (2.0^106 kg)^ 9.8m/s^2...

I am very new to physics so I am still learning a lot. Here is my attempt: Find the net force acting on the block : Fnet= Fg+FN so I have to find FN before I can complete the answer. FN = Fg (mg) FN = (0.72kg)(9.8m/s^2) = 7.056 or 7.06 N Fnet = 9.8+7.06 = 16.86 N or 16.9 N To find the...

the question is find the value of E1 that would make the ammeter reading = 0 ? i tried KCL , and KVL and got the following equations : ( I1 belongs to 3 ohm , I2 belongs to 2 ohm , I3 belongs to 4 ohm ): I3 = I1+I2 E1 = 3I1 + 4I3 12 = 2I2 + 4I3 but now i have 3 equations in 4 variables ?! i...

Find the resultant vector of vectors A and B shown in the figure. Solution: By geometry method: Cosine law for the right side triangle. ##R^{2} = 17^{2} + 44^{2} - 2 (17)(14).cos 70^{0}## ##R = 41.39 m/sec## By Sin law, ##\large\frac {R}{Sin 70^0} = \frac {17}{Sin\alpha}## ##sin...

I have read that Hubbles law states that a galaxys speed as it moves away from us is proportional to it's distance. Does this have an upper limit? If a galaxy 1 megaparsec is moving at 70 km/s, a galaxy 10,000,000 mgp away is moving faster then light. Or am I (most likely) mistaken?

The second law of thermodynamics tells us that the amount of useful energy in an isolated system tends to decrease. Does this imply that mankind will reach a point where it cannot longer use any kind of energy? If so, do we have an estimate of how long it will be necessary for to haven't useful...

$$\sum F_x = T - w_x - f_k = ma_x $$ $$ T = mg\sin(\theta) + mg\cos(\theta)\mu_k + ma_x$$ $$ T = (9.8 \frac{m}{s^2}) \cdot (\sin(41^{\circ}) + \cos(41^{\circ})) + (75kg)\cdot(0.25\frac{m}{s^2}) $$ $$T = 672.91 N $$ Having found the tension force, I can find the work done by the person who's...

In material introducing Newton's First Law to students, we sometimes see a supplementary statement to this effect: in addition to changing the velocity of an object, forces can distort its shape. But surely here two different situations are being conflated: (1) the effect of a single force on...

The first law of thermodynamics states that matter can only be transferred from one state to another, and cannot be truly destroyed. What happens to matter consumed by a black hole? What happens to it and where does it go? Does the first law still hold true?

I've set up a simple experiment to look at the ideal gas laws. My experiment is relatively simple in that I have a metal tube which is capped on one side. I am then pressurising the tube with air to 100 psi and locking it off. My thought is that as the pressure increased, with volume held...

I am searching all over google, I didn't find any problems on polygon law.

for this diagram, I want to use Triangle law of forces, but I am not sure about final answer. So how can I know which law of force should be use to calculate magnitude and direction for any diagram?

Problem Statement: Derive the optical law of reflection. Hint: Let light go from the point A (x1, y1) to B (x2, y,2) via an arbitrary point P = (x, 0) on a mirror along the x axis. Set dt/dx = (n/c) dD/dx = 0, where D = distance APB, and show that then theta = phi. Relevant Equations: t = nD/c...

In "An Introduction to Modern Cosmology" by Andrew Liddle, page 130, paragraph A2.3 Luminosity distance, explains why the inverse square law does not hold at very far distances. One reason given is the expanding universe. (Another was the geometry of the Universe.) Could there be also...

1. Drawing Free Body Diagrams for all components we get : 2. Following this we can find total elongation using ##\Delta L = \frac {1}{AY}(F_1*L_1 + F_2 *L_2+ F_3 *L_3) ## My questions : a) I am assuming that the internal forces (3t) are neglected in the FBD because of Newton's third law whereby...

Please refer to diagram. V1 is open initially then V2 is open for 5 minutes for pressure to equalize. V1 and V2 are then shut. V3 is opened. What is Vol 2 ? P(final)*V(final) = n(final)* R*T => (Vol1 + Vol2) = n(final)*R*25C/ 0.070 Torr where n(final) = n(Vol1) + n(Vol2) If I shut V3, I...

Equating the two equations gives me ##k = -\frac {YA}{L}## but the correct answer of the same magnitude but opposite sign. I think the nub of my misunderstanding is quite elementary (who would have guessed!) : When is it ##F=kx## and when is it ##F=-kx##? If I understand correctly, F is the...

1.If so what would the law mean if ##T_{surroundings}>T##? 2. Stefan-Boltzmann Law is formulated as ##H = A\sigma T^4## where ##H## is the energy emitted per unit time, ##A## is the area of the object, ##T## is the absolute temperature of the object and (3.) I am unclear about whether...

First, I started with F_a = m_aa_a=G \frac{m_am_b}{r^2} and F_b = m_ba_b=G \frac{m_am_b}{r^2} . Solving for their respective accelerations, I got a_a=G \frac{m_b}{r^2} = 100G and a_b=G \frac{m_a}{r^2} = 100G, meaning that the initial acceleration of the two point particles are each 100G ...

I'm reading a biology paper which uses LaPlace's law in the analysis. Basically the tension within a spherical pressure vessel is half the product of the radius and pressure. I'm trying to understand how this equation is derived but don't have a strong background in fluids or physics so I'm not...

I'm trying to derive the lever law by myself, however, I'm stuck. Please follow the logic of my calculations. Every object in the picture has the same mass. I want to prove that, under the effect of the gravitational force, I can replace the objects in A and C with the two objects in B, and...

I know how Gauss law helps us to calculate the discontinuity at a point on the surface of a surface charge. Similarly using Gauss law, is there a way to determine the continuity at other points of electric field due to a surface charge or the continuity at all points of electric field due to a...

Problem Statement: The effective charge density of the electron cloud in a hydrogen atom in its quantum mechanical ground state turns out to be given by pnot(e^-(r/rnot)), where pnot is a negative constant (the clouds charge density at r=0) and rnot is a constant (rnot=0.025nm). Use gauss's law...

Zemansky defines Heat as : When a closed system whose surroundings are at a different temperature and on which diathermic work may be done undergoes a process, then the energy transferred by non mechanical means, equal to the difference between the change in internal energy and the diathermic...

Above is an example figure. 2. When a ring in a changing magnetic field is not complete (i.e. open circuit with a small gap), how to analyze the emf of the ring? According to the general form of Faraday's law, ## \oint \vec{E} \cdot d \vec{s} = -\frac{d \Phi}{dt} ##, I deduce that although it...

Hello everyone new here :) I've recently enrolled myself in a computer technician course and I've encountered a few (basic) electrical sums. I have absolutely no electrical background, and the course mentioned no requirement of such, but I'm already being presented with work I have no idea of...

I'm having trouble wrapping my head around some thermodynamics and ideal gas law concepts. I don't have a specific textbook question but Just a concept I'm having trouble with. What I'm struggling with is understanding some of the relations between pressure, volume and temperature...

in Clausius formulation, what does the phrase "from cold to hot" means? I can understand it intuitively but in the language of the zero and first laws, we have not defined a temperature scale, only equivalence classes of systems that will be in equilibrium with each other (systems with the same...

I'm thinking through a few basic things - hopefully in a new way. One thing that struck me is that momentum (mv) and energy (e.g. 0.5mv^2) can be conserved but velocity is not. For one thing, velocity is relative, of course. I'm wondering whether there's a quantity a bit like velocity but not...

1) Take a non-steady circuit such as an LR circuit. Why does Kirchoff's voltage law work when analyzing such a circuit? Is it because we're assuming that dI/dt and thus dB/dt are approximately zero thus meaning that curl E is approximately zero? 2) ε, the electromotive force, is the line...

If we have an object in space (deep space where it is under no other gravitational influence) and we push it a little so that it gains some velocity and after some time comes into the influence of a planet's gravitational field and crashes on it. Where is that energy from the crash coming from...

Hello. As I understand it, Kepler's 2nd law of planetary motion can be explained through conservation of energy or conservation of angular momentum. I am having trouble with the conservation of energy explanation. We know that the sum of potential and kinetic energy of a planet in orbit around...

Here are the two questions I want to compare: 1. A student of mass 62 kg stands on an upholstered chair containing springs, each of force constant 2.4 × 103 N/m. If the student is supported equally by six springs, what is the compression of each spring? 2. A 0.20-kg ball attached to a vertical...

Hey guys, Have a thermodynamics exam coming in the next few days up based on the following topics. Energy and first law, Thermodynamic properties, First law: closed systems, First law: open systems/specific heat. When I have taken a look at the past exams it has been all calculations and...

I assumed the current flows from the 20V so, 20V - 100 (i1) - Ri2 = 0 First loop 20V = 100i1 + Ri2 Second loop +Ri2 + 40V - 200(0.08) = 0 Ri2 = -24 Back to equation 1 20 v = 100i1 + (-24) therefore, i 1 = 0.44 For loop two: i1 - i2 = i3 0.44 - i2 = 0.08 therefore i2 = 0.36 ohms...

I'm familiar with the history of the concept of the square-cube law going back to Galileo, Watt, etc. However, I don't know the origin and history of the language we use to talk about it today. When was the specific term "square-cube law" coined? When did that name become commonly...

I have been studying electromagnetic induction and have looked at the laws of Faraday and Lenz. Faraday's law makes perfect sense to me, but I can't seem to grasp Lenz's law. I have read about it and watched many yt videos, and the idea seems simple. But actually using it to predict e.g. the...

let's assume I have 2 systems A and B. the surface that describes when the 2 systems are in equilibrium is given by F(a1,a1,...,b1,b2,...) = 0. assuming we can write this surface as A(a1,a2,..)=B(b1,b2,...) why do A and B describes the temperature function of the systems? in class, we...

The force of the sphere increases because according to Coulomb's force increases as the distance decreases. I'm not sure if this is correct.

I would like to make a program that produces a 2D heat map showing the magnitude of the magnetic field produced by a finite length solenoid. The heat map would show the field strength along the radial and axial directions of the solenoid. I plan to divide the conductor into "infinitessimally"...

Hi I am a yr 1 undergraduate law student (LLB) considering transferring to physics. Physics was my favorite subject in high school. My worries: not sure if I can master uni math. High school math is okay but I was not the smartest student in math. I am not reading physics in my free time. I...