Laws Definition and 1000 Threads

Here is my attempt at setting up the equation: I set up the equation to find the acceleration of the box: F-Ffr= m*a after finding the acceleration, I can use the acceleration and plug it in the formula v^2=(v0)^2+2*a(x-x0), which will get me the value of (x-x0)The solution sheet says that F...

Paul Dirac proposed a hypothesis called "Large Numbers Hypothesis" (https://en.wikipedia.org/wiki/Dirac_large_numbers_hypothesis), where he basically stated that, if he was correct, laws of physics would change with time. But what about fundamental laws and constants? (Not only 'effective'...

So first of all ,we all agree that Universe exists and it is not totally chaotic , it seems to have some laws that govern its behavior. Would we ever be able to fully discover and understand the true laws of the universe. Or human intelligence is limited (the way the human brain is constructed...

I've been trying to use KVL/KCL here but I can't get any. The only thing I accomplished is R6 has 0V, 0A (KVL with its loop). All the other ones I can't get any? Thanks

According to physicist John Wheeler, the universe is part of a sequence of cycles of Big Bangs and Big Crunches, called cyclic or oscillatory universe model (https://en.m.wikipedia.org/wiki/Multiverse (Mentioned in "Classification schemes") According to this author, in each cycle, the laws of...

In Newtonian mechanics, conservation laws of momentum and angular momentum for an isolated system follow from Newton's laws plus the assumption that all forces are central. This picture tells nothing about symmetries. In contrast, in Hamiltonian mechanics, conservation laws are tightly...

Summary: Could MWI (Many Worlds Interpretation) create universes with fundamentally different physical laws? Physicist John Wheeler proposed along with Hugh Everett and Bryce DeWitt the 'Many Worlds' Interpretation of Quantum Mechanics (although he expressed some doubts about its validity) I...

At the moment of throwing the ball the ball will have a vertical vel of 4 and horizontal of 3 wrt to elevator so as seen from inside the elevator the ball will behave like a projectile where g(eff) = 8 and with time period 1 sec hence range will be the displacement which should be 3 m but ans...

unsure what process to tackle it.

Hi, I'm worried I've got a grave misunderstanding. Also, throughout this post, a prime mark (') will indicate the transformed versions of my tensor, coordinates, etc. I'm going to define a tensor. $$T^\mu_\nu \partial_\mu \otimes dx^\nu$$ Now I'd like to investigate how the tensor transforms...

a) Kepler's first law states that a planet like Earth displays an elliptical orbit with the sun in focus. Using M = dL/dt, prove that a planet cannot leave its plane of orbit. Note: M here is an externally applied torque that the sun exerts on the planet. diagram of the situation described b)...

The problem with this is that only one push's worth of energy was expended. One push's worth of input cannot produce two push's worth of output, for this would violate the law that says you can't get more movement out of something than the amount of force you exert onto it (to put is very...

How would the first and second laws of thermodynamics apply to the creation and existence of the universe? I'm not a physicist (and unfortunately, do not remember a lot that I learned in Physics class in school and college about Thermodynamics). I did some searching and I have come across an...

Problem Statement: Are this 3 topics comes under laws of conservation of momentum? Relevant Equations: Are this 3 topics comes under laws of conservation of momentum? Are this 3 topics comes under laws of conservation of momentum: energy lost due to impact, inelastic impact, purely elastic...

Problem Statement: Hello! I'm trying to learn how to know if a particular interaction is allowed or forbidden. I found 3 decays which i can't understand. Relevant Equations: The decays are: 1) \eta \rightarrow \pi ^{0}+\gamma 2) \phi \rightarrow \rho^{0}+\gamma 3) \eta \rightarrow \pi...

I know what the answer is supposed to be, but I don't understand why. Here is my logic as to why I thought a few of these suggestions should be the right answer. "C) Mass is a measure of an object’s ability to resist motion or movement of any kind." Considering F = ma, and that mass is...

Helping my daughter with her math and hit this one and not sure how to advise. All help welcome(x-2y10)3 / (x-4yz4)-5 This one throws me off because I don't know how to deal with the z, as only on the right side of the divide

So imagine there are now two dimensions of time, instead of the one dimension which we're used to. The laws of physics which we're used to won't make anymore sense unless they're adapted for the two dimensions of time. How would you adapt them?

Hi Guys, The problem I am facing at the moment is to calculate the appropriate setpoint for a set of pumps supplying cold water to a building so that electricity and cost savings can be achieved. Here is the situation: There are three pumps connected in parallel. They are located on the ground...

I'm taking a break from music for a few days because I do that sometimes, and it's like a rule for me, and I usually listen to music when doing my physics homework. I'm realizing I have a little more trouble without that boost I get. But it could also be that what I'm trying to do is hard. I...

Homework Statement From reliable information, once Baron Münchhausen was stuck in a swamp, he pulled himself out of it by the hair. What laws of physics did the baron break? (Find the answer analytically) Homework Equations None. The Attempt at a Solution Well, I think that he breaks the...

Homework Statement I have a double incline mass problem where Φ=43° and θ=20°, mass_A=1.00kg and they are connected by a massless string where the net force of each block is equal to 0. Homework Equations I believe I am to use Newton's 2nd law to find the force of the tension which I have next...

Hi. Pascal's law states that static pressure in a confined incompressible fluid without gravity is the same everywhere. Is this law derivable from more fundamental laws? Some thoughts: Is Pascal's law part of the definition of the liquid state? If the liquid operates between two hydraulic...

I just did my morning exercise while listening to a short youtube talk on genetics. I do not understand it but what struck me was it seemed to be on the level of an EE discussing OHM's law, Transistor theory, and digital logic terms. Now I know all the rules that make my PC on which I am...

The “Laws of Physics” arise from and reflect the lawful regularity of the physical universe. Absent that underlying lawful regularity there would be no laws of physics.Is it true that the laws of physics are descriptive of that underlying order, but are silent on the nature of its origin, of how...

I'm reading Scheck's book about Mechanics and it says that Newton's first law is not redundant as it defines what an inertial system is. My problem is that we could say the same about Newton's second law. Indeed, Newton's second law is only valid, in general, for inertial systems, so it also...

Hi, I’m just wondering about this: Are there any theoretical reasons why physical laws take the form of 2nd order (in time) differential equations? Or is it just observed to be that way? Are there ANY laws (even in a limited context) which are 3rd (or higher) order in time?

In my post that I have been ranting on trying to figure out how to solve things on everyday occurrences. Which was titled "Mass of a Piston" That is to say, can you use physics on the spot to calculate a golf swing that projects a ball off a cliff that you have never seen before. You don't know...

I'm a little confused with the application of laws of motion on a man climbing a rope. Suppose a man of mass Mg is climbing a rope with an acceleration a. Rope is massless. Now if look through the frame of the piece of rope held by the man, there is a force Mg downward by man, ma downward...

Homework Statement we are asked to compare the graphs of 0.5^x with 2^x using index laws Homework Equations I am not sure how the regular index laws apply The Attempt at a Solution All I can say at the moment is the the graph of 2^x is a reflection of 0.5^x in the Y axis. I don't know...

I am starting to search data on what actions are to be made for living longer. I might have to know the working of human body, but it might take lot of time. Within the time I know the working of human body, and have custom actions for me to live longer, to eliminate me not do any of the random...

Homework Statement [/B] A child sits on a sled (50kg) on a snowy hill with an incline of 5 degrees. The coefficient of static friction is 0.05. What downward force must a parent apply parallel to the normal force, to prevent the child from sliding down the hill? (Answer: 366N)Homework Equations...

Homework Statement Use Kirchhoff's Law to find the current I in the circuit shown below. Choosing the best loop can simplify the problem. (a) Which loop in the circuit should you choose? (b) Calculate the current I Homework Equations Kirchhoff's Second Law ∑V = 0 and the junction law ∑I =...

Homework Statement Evaluate: $$\lim_{θ \rightarrow 0} {\frac{1-cos θ}{sin θ}}$$ Homework EquationsThe Attempt at a Solution By using trigonometric identities, I get to: $$\lim_{θ \rightarrow 0} {\frac{sin θ}{sin θ}}⋅\lim_{θ \rightarrow 0} {\frac{sin θ}{1+cos θ}}$$ By using the Limit Laws, I...

I was just curious to know, how do we know our laws of physics are correct? How do we know the laws about time or space aren't overruled (we say time flows forward, but how do we know that it can't skip back or flow backwards), because we just haven't seen it or can't perceive it?

In physics, at least at my level of knowledge and understanding, a lot of the most basic facts of reality start to seem a bit arbitrary. Mostly this seems to be the case with the various universal constants such as the speed of light or plank's length or the gravitational constant. So what I...

The problem is attached in the photo. The correct answer, according to the teacher's solution, was obtained using conservation of energy. Initially I tried using Newton's law/kinematics and got the wrong answer. Why didn't this work? Can you ever use Newton's law/kinematics to solve pulley...

Homework Statement It’s a rather confusing circuit, I’m having problems trying to understand the way current circulates through the circuit. Homework Equations Kirchoff’s DC circuits laws only, no resistive simplification neither nodal analysis The Attempt at a Solution I’ll attach my intent...

My question is related to the book: Classical Mechanics by Taylor. Section 7.8 So, In the book Taylor is trying to derive the conservation of momentum and energy from Lagrange's equation. I understood everything, but I am struggling with the concept and the following equation...

How do i apply the laws of refraction to plane and curved surfaces. I have absolutely no idea how to even start on this one, its got nothing to do with the course, i am going to study. i need to understand this to move on but i genuinely have absolutely no interest in optics. I really can not...

Recently I was watching Lawrence Krauss on YouTube talking about the universe originating from empty space, which seemed to make sense when he described that nothing isn't really nothing. Then he later in the video he asked the question of whether multiverses would also follow the same laws of...

Do the laws of thermodynamics basically establish its properties? I got to thinking, and it seems that the main purpose of the laws of thermodynamics is to establish that the thermodynamic properties. 0th & 3rd - establish Termperature as a valid property via ability to have equality & scale...

Here are Newtons Laws 1. A particle at rest stays at rest or continues to move in a straight line at constant velocity unless acted on by a force. 2, Force is mass x acceleratoion 3 To every action there is an equal or opposite reaction. What are they saying? Well 1 follows from 2 which...

Homework Statement If a falling object overcome 72 metres in 6 second, how much distance it overcame in first 3 second. Homework Equations s = ut+(at^2)/2 The Attempt at a Solution Here, s = 72 m u = 0 t = 6s a = ? We know, s = ut+(at^2)/2 Or, 72 = 0*6 + (a*6^2)/2 Or, 72 = 36a/2 Or, 72 = 18a...

Homework Statement A gun fires bullets each of mass 1g with velocity of 10m/s by exerting a constant force of 5 g weight. Find the number of bullets fired per second (take g=10 m/s2). Homework Equations F=ma M1U1 + M2U2 = M1V1 + M2V2 (conservation of linear momentum) The Attempt at a...

I've been caught by a quite interesting statement of Berkeley physics Course Vol.1 (Chap. 5), that says "In the physical world there exist a number of conservation laws, some exact and some approximate. A conservation law is usually the consequence of some underlying symmetry in the universe."...

Hello guys, I am a bit confused. Is it that PV/T=constant for ALL the processes of ALL cycles, like Otto, Diesel, Rankine? I know that PV=mRT, so does that mean that PV/T=constant all the time? Secondly, I am a bit confused as I read that PV^γ=constant. What is that exactly? Where does it come...

Homework Statement Two crates, A and B, are in an elevator as shown. The mass of crate A is greater than the mass of crate B. a. The elevator moves downward at constant speed. ... iii. Rank the forces on the crate according to magnitude, from largest to smallest. Explain your reasoning...