Laws Definition and 1000 Threads

Do we understand how the physical laws of the universe created biology? How can we explain cell division, consciousness, evolution, as a product of matter operating in a universe governed by laws?

Hi, I'm trying this summer to finish my mathematical methods book. I'm investigating right now the chapter of complex numbers, the end of the chapter has some applications in electricity and how can complex numbers make the work easier. The problem is that I didn't found it easier nor...

How did Kepler derive his laws of Planetary Motion without knowing about Newton's law of gravitation? Specifically, the first law of planetary motion which says that planets follow elliptical paths - how did he figure that out without the knowledge of the gravitational pull of the sun? Was it...

What ensures conservation of energy and conservation of momentum in Electron-Positron annihilation? If e=mc2 and momentum = mass*velocity, couldn't the energy equivalence of the electron and the positron be converted to make one photon, or more that 2 photons? I've read that two photons are...

In QM there is no cloning theorem that says "we can't clone or erase quantum state". But in classical macro world we can copy information and erase it. If we should describe classical information as a very complex quantum state then we shouldn't be able to copy or erase it, right? And obviously...

Homework Statement A monkey which has a mass of ##m## is hanging on a rope as the picture shows. Then the monkey starts to move upwards with speed ##u##. Find how the box which has a mass of ##2m## will move. Neglect friction between the rope and pulleys. Assume that pulleys are massless...

Homework Statement Question: Figure 1: QUESTION ABOVE. Homework Equations The Attempt at a Solution :[/B] P + P → K+ + K- + P + P Firstly, I just wanted to check that this is correct. I found the answer pretty quickly by googling it but have since spent a long while trying to understand...

I just made a rail gun using two ring stand poles, a steel ball, and a car battery. Maximum velocity is about 5 cm/sec. What is strange is that it is shooting the wrong way. Defying the laws of physics and right hand rule. Any ideas ?

Homework Statement a. Determine the currents I1, I2, and I3 in the above figure. Assume the intermal resistance of each battery is r = 2.48Ω. Homework Equations Kirchhoff's Laws (Junction Rule and Loop Rule) The Attempt at a Solution Using Kirchhoff's Laws, I ended up with three equations...

Hi Mentor i am in little confusing about force, according Newton third law force on action and reaction is equal but according hydraulic system are not equal. https://www.facebook.com/photo.php?fbid=1749685448591067&set=pb.100006488851023.-2207520000.1429362639.&type=3&theater Thank you for...

I have impression that physicists consider QM laws as fundamental, meaning that there should be a way how QM mathematical form is realized in reality. On the other hand QM laws could be effective laws resulting from some process of evolution. In that case it should be possible to characterize...

Three identical blocks are pushed across a table at constant speed. The hand pushes horizontally. Let the stack of two blocks be system A and the single block be system B. Now suppose the mass of each block is 2.5kg, the coefficient of kinetic friction between the bottom surfaces of the blocks...

Hi, I know this is a basic question however, I am seeking absolute verification on these two points. 1) Quantum Mechanics is a set of Laws. 2) Laws only describe what we see. Theories give us the reason behind them.

Homework Statement I am stuck on 2 and 3. I attached all the problems and variable and unknownsHomework Equations I attached my work for 1, 2, and 3. I'm not sure if it is right though. [/B]The Attempt at a Solution Can someone check my work for problems 1, 2, 3 and 4? The equations...

I am a 10th grade student, and I tried for a few weeks now to find a proof to Kepler first and second laws. Is there a simple proof to Kepler' s laws?

I'm a little bit confused about the relationship between Galileo's Principle of Relativity and Newton's Laws. Indeed, as I understand, the Galilean Principle of Relativity is what Galileo presented with Salviatti's ship discussion. The discussion seems to lead to a simple idea: "if one performs...

Greetings all, I know that Faraday's and Ampere's law are related by M.E., but can I say the following? By Faraday’s Law, a time varying magnetic field induces an electromotive force, which produces an electric current density in a media. Up until EMF, that's Faraday's, but is the rest of...

Specifically the equations you get when you examine the loops in a circuit.

I have a conceptual question. There is a law in science for every phenomenon in nature, like gravity or electric field. But also there are laws for springs or capacitors etc... I mean the engineering materials that are produced by engineering processes, not can be found in the nature itself...

Homework Statement 5 lbs of nitroglycerin detonates. What is the total volume of the gases produced? Homework Equations PV=nRT The Attempt at a Solution I used the balance chemical equation of the decomposition of nitroglycerin and used stoichiometry to find the number of moles of nitrogen...

Greetings historians of physics! Newton's Principia is written almost entirely using geometrical proofs and diagrams, barely using any calculus at all. It is thought that Newton was reluctant to use his calculus in this work, fearing that it would undermine its credibility and reception, since...

Homework Statement Homework Equations None... Newton's laws The Attempt at a Solution Not the attempt, the entire solution is: String length is constant...hence if on the right side of the pulley, the string goes up by x distance then on the right side also the string goes down by x...

I am trying to understand Bernoullis from Newton laws applied to molecular dynamics (as opposed to conservation laws) From the conservation laws I understand for a incompressible invicous (experiencing no friction effects ) Ideal fluid Mass is neither created nor destroyed Mass in = Mass...

Hi Guys, I was wondering; if electronic charge is conserved by Kirchoff's Current Law, then does this mean that the total number of electrons traversing any given circuit at any time is constant?

Homework Statement To hoist himself into a tree, a 72 kg ties one end of a nylon rope around his waist and throws the other end over a branch of the tree. He then pulls downward on the free end of the rope with a force of 358 N . Neglect amy friction between the rope and the branch, and...

Homework Statement A 225 kg crate rests on a surface that is inclined above the horizontal at an angle of 20o. A horizontal force (F = 535 N parallel to the ground, not the incline) is required to start the crate moving down the incline. What is the coefficient of friction between the crate and...

Homework Statement The drawing shows a large cube (mass = 25 kg) being accelerated across a horizontal frictionless surface by a horizontal force P. A small cube (msmall = 4 kg) is in contact with the front surface of the large cube and will slide downward unless P is sufficiently large. The...

Homework Statement You've attached a bungee cord to a wagon and are using it to pull your little sister while you take her for a jaunt. The bungee's unstretched length is 1.3m and you happen to know that your little sister weighs 220N and the wagon weighs 75N. Crossing a street, you accelerate...

I've tried to relate Biot-Savart's Law to Ampere's and I've found a contradiction, which I guess is due to a naive use of Ampere's. If ## \int \vec B · d\vec l = \mu_0 I_{enc} ## is applied to a circle of radius R around a current element ##Id\vec l## we have ## B·2\pi R = \mu_{0} I_{enc} ##...

Homework Statement Determine the magnitudes and directions of the currents through each resistor shown in Fig. 19-38. The batteries have emfs of http://www.webassign.net/images/scriptE.gif1 = 9.0 V and http://www.webassign.net/images/scriptE.gif2 = 17.0 V and the resistors have values of R1 =...

Homework Statement Determine the currents I1, I2, and I3. R5 = 18http://www.webassign.net/images/omegacap.gif. Assume the internal resistance of each battery is r = 1.0 [PLAIN][PLAIN]http://www.webassign.net/images/omegacap.gif. Homework Equations Kirchoff's Loop Rule: I1+I2+I3=0 Kirchoff's...

Homework Statement As simple as the question may seem, I require some honest help. I'm particularly new to physics. The question is the following: A net force of magnitude 4.0N acts on a body of mass 3.0kg for 6.0 s. The body is initially at rest. Which of the following is the speed of the...

Homework Statement Prove that \lim_{x->a}[f(x)+g(x)]=\lim_{x->a}[f(x)]+\lim_{x->a}[g(x)] Homework Equations Epsilon/delta definition The Attempt at a Solution The book says: Let the limit of f(x)=L and the limit of g(x)=M. Then, \mid f(x)-L \mid<\frac{\epsilon}{2} whenever 0<\mid x-a...

If you keep boling water in thermos It remains hot up to 3-4 days. Let's say you can create a thermo where no heat can escape outside. Does the water remain hot for decades? Or does it get cold even if heat does not escape? And why? What is the corresponding laws of thermodynamics about thermal...

Using logs to compute the following, to the four-figure accuracy. $\frac{.009292}{(\sqrt[3]{582400}+14.23)}$ Let N=$\frac{.009292}{(\sqrt[3]{582400}+14.23)}$, then $\log\left({N}\right)=\log\left({\frac{.009292}{(\sqrt[3]{582400}+14.23)} }\right)$. Log N=...

Homework Statement A car with mass 2500 kilograms travels along a straight level road at 90 km/h. A headwind begins to blow with a force of 200 N causing the car to slow down. Calculate the car’s deceleration. Homework Equations The book uses the formula F =ma so 3. Book's solution = 0.08...

Dear friends! I had read about a comparison of laws of thermodynamics as follows. " If energy extraction is a game. First law: You cannot win the game. Second law: There is no break even. Third law:You can not leave the game". My problem is that I cannot convincingly understand the comparison...

How can we sure that physical laws are always the same in all the universe?

Q1: Are objects at rest or are they in a uniform motion along a straight line in the world and in the universe? Q2: Why does an object with an important inertia not move if I apply to it suddenly a big force (accelerate it rapidly)? And on the other hand, the same object does move with a small...

What i basically mean by this is that at this point in time we have classical and quantum physics, both need a different set of rules to describe their phenomenon due to the size of their appropriate systems why is this and does that mean we could also say the same for immensely large systems...

In electrostatics, ∇ × E = 0 so E that is a conservative field and there must be sources of E from which E flows. We know that this sources are the electrical charges given by Gauss' Law. But when B changes in time, ∇ × E = - ∂ B / ∂t. Now the Gauss' Law no longer applies and if there are not...

derivation of wiens displacement law and wiens distribution law from thermodynamic principle.but not from Plancks law

Homework Statement A 1490 kg car is is traveling at a speed of 22.2 m/s when the driver let's the car coast on a level road. The friction on the car slowing it down is 288 N. How far will the car coast? Homework Equations f=maThe Attempt at a Solution i can find the force but i cannot find...

Any one who can help me to get notes on Kitchoff's laws so i can understand them well

Homework Statement An asteroid of mass m is in circular orbit of radius r around the sun with speed v.It has an impact with another asteroid of mass M and is kicked into a new circular orbit with a speed 1.5v.What is the radius of the new orbit in terms r?[/B]Homework Equations (v1)^2/(v2)^2 =...

Homework Statement Two blocks are pushed to the right so that they move together with increasing speed. Block B remains at the height shown. Ignore friction between the ground and block A but not between block A and block B. The mass of block A is 10kg and the mass of block B is 2kg. Let...

Hi, I'm trying to use Kirchoff's voltage law to find a system of equations which I can use to find I1, I2, I3, I4, and I5; which are the respective currents going through each resistor in the image. I have 5 unknowns so I need to find 5 non redundant equations. The problem is, every system...

Well, I do understand what mathematical theorem means, and I also know what differential equation is but I don't really get why sometimes certain things are called "equations" instead of "law" (Maxwell's equations, nobody calls it Maxwell's laws) and conversely some equations are called laws...

Homework Statement See above diagram for full details of the circuit Variables used: Assumption: direction of current is clockwise and the loops are positive in clockwise as well. Current through 1000 ohm=i1 Current through 4700 ohm-i2 Current through 2200 ohm=i3 Current through 1200...

Homework Statement An Astronaut on a spacewalk has an oxygen tank strapped to his suit. The oxygen in it is pressurised to 5 atmospheres (5x10^5 Pa), and the volume of the tank is 15 litres. a) The oxygen is pumped to his mouth at atmospheric pressure (1x10^5 Pa). What is the maximum volume of...