Laws Definition and 1000 Threads

Homework Statement Max (65 kg) pushes Toni (50 kg) with a force of 360 N. The force of friction is 0 on Toni and 80 on Max. (a) Find each girls acceleration (b) If Max pushes Toni for 0.1 s, how far will Toni travel in 0.5 s? Homework Equations Fnet=ma v2=v1+at d=v1(t)+1/2a(t)^2 The Attempt...

Homework Statement Homework Equations Kirchhoff;s first and second law, V=IR The Attempt at a Solution Tried the question as follows: V= 24/(2+6+4) = 24/12 = 2V (pd from top cell) then did 2=4 I3 therefore I3 = 0.5A and then 2 = 6I2 I2 = 0.33A and I1 = 0.5+0.33... =0.83A?

Homework Statement Homework Equations V=IR and kirchhoffs laws The Attempt at a Solution Number three is my attempt at finding a solution but I got stuck when I had to find an expression for loop one on the diagram. Thanks in advance for your help...

Suppose we have a body of finite size which can be translated, rotated, compressed and stretched. We have every information about the body. We have its dimensions and everything. We have its mass and density. But, since I'm here talking about a completely generalized version, so we have variable...

1. Homework Statement A DC circuit is shown below. Note the ground (V=0) in the circuit 1- calculate the current through the 5Ω resistance. Use "+" sign for the current directed from right to left, and "-" sign if the current flows from left to right. 2- The sign of the potential at a is...

Homework Statement Homework Equations F=m*a ΣF=0 The Attempt at a Solution Firstly, I tried to work on the normal force of bowling ball. But I can't get the answer. I don't get the idea that bowling ball could be kept at constant height, I didn't really understand the question guess. Can...

I've lately began working with Newtons laws problems at school again, and I've already ran into a few problems. When making calculations and solving problems, it is often nessecary to understand when forces are equal to zero, and when they are not. Since every force has an equal and opposite...

I'm an attorney trying to invalidate a patent that I believe is directed to patent-ineligible subject matter. It's been an interesting exercise, and I'd love to hear other ideas/suggestions/etc. on how to approach it. At a high level, the patent claims certain structures with a certain...

Homework Statement Determine Currents ##I_{1}, I_{2}, I_{3}## Homework Equations Kirchoff's Rules: $$\sum_{i=1}^n I_{i} = 0$$ $$\sum_{i=1}^n V_{i} = 0$$The Attempt at a Solution Basically, I'm not sure if I'm applying the Loop Law correctly. For example, in Loop A, going clockwise from...

I am hoping that I can have someone look over my answers. I have provided what I think is necessary to be appropriate posting, including the questions and attempts at all my answers. I would just like some feedback that I am correct in my answers. Thank you! This is an overview that all the...

Consider a 4 current J^\mu and a metric g then conservation laws will require \del_\mu J^\mu = 0 my lecturer gave me a brief problem and I think I'm missing some understanding of it he writes What I'm not understanding is, where he states, if we choose B to be the time slice between etc...

Homework Statement One or more external forces are exerted on each object enclosed in a dashed box shown in the figures below. Identify the reaction to each of these forces, assuming that (b) occurs on Earth. Select all that apply. (b) the wagon exerts a force · downward on the Earth...

Homework Statement Consider a uniform rod of mass 12kg and length 1.0m. At it's end the rod is attached to a fixed, friction free pivot. Initially the rod is balanced vertically above the pivot and begins to fall (from rest) as shown in the diagram. Determine, a) the angular acceleration of...

Homework Statement http://postimg.org/image/ys43ylstp/ [/B] I need to find tension and current in each element of the circuit. I have included an image of what I have drawn so far for the circuit. http://postimg.org/image/ys43ylstp/ Homework Equations Kirchoff's laws. The Attempt at a Solution...

Hi. In the (mainstream) books of electrodynamics I know, the electric and magnetic fields are introduced as force fields normalized to a charged test particle of 1 C. This makes those fields appear as an unnecessary, but convenient mathematical tool. They cannot be measured in the absence of...

Here's a thought from other thread A reply So what's the relation between gravity and the laws of thermodynamic, or should it be conservation of energy?

Reading the English translation of Einstein's seminal paper on GR. http://einsteinpapers.press.princeton.edu/vol6-trans/90?ajax This paragraph below on p78 doesn't make much sense to me. Could you provide a second English translation or even adding math notation. "Before Maxwell, the laws...

Hello everyone! I want to proof that: ##p \land (p \to q) \Rightarrow q## I know this is a quite trivial problem using truth tables, however, I want to do it without it. As I'm learning this myself, is this the correct approach? ##p \land (p \to q)## ##\iff p\land (\neg p \lor q)## ##\iff (p...

Homework Statement A block of mass ## m ##, attached to a rope, is dropped at the point A. When the block reaches the point B, the tension is ## T = 2 \cdot m \cdot g ## and the rope broke at that same point. If the length of the rope is ## L = 6cm ##, evaluate the height ## h ## where the...

I've been noticing that there are exceptions to every scientific law. For Example, with Newton's First and Second Laws are totally invalid at the quantum level, but I'm failing to find such an example for Newton's Third Law. Is anyone able to help me?

9/1/2016 Orbital mechanics Wikipedia, the free encyclopedia This reference states: "General relativity is a more exact theory than Newton's laws for calculating orbits, and is sometimes necessary for greater accuracy or in highgravity situations (such as orbits close to the Sun)". Can GR...

So, I'm reading a physics book, and it talks about Newton's three laws, of course, but then after that it says that if a force of f pushes on an object at angle Θ, then the force in the x direction is f ⋅ cos(Θ), and the force in the y direction is f ⋅ sin(Θ). Where did THAT come from? Do we...

Homework Statement The chain comprising three rings (each of mass ##0.25kg##) is suspended from a massless rope, and a pulling force ##\left(F=9N\right)## is exerted upwards on the rope. Picture: http://i.imgur.com/xeaiBsc.jpg?1. I need to find the values of all the unknowns. Homework...

Homework Statement Two cardboard boxes full of books are in contact with each other on a friction less table.Box H has twice the mass of Box G. If you push on box G with a horizontal force F, then box H will experience a net force of? 2. The attempt at a solution Let book G's mass be = m...

Howdy, Was wondering if you guys would mind critiquing, correcting, or adding any good insights to the following which was posted elsewhere by me, thanks! ________________ ... remember a ways back there was a finding that went viral about the speed of light not being constant? I forget the...

Whose observations did Kepler use to prove that planets do in fact orbit in ellipses ?? Was it Tycho's observations? Thanks.

Within the context of Newton's laws, it seems implicitly understood that mass is an additive property of objects. My question is: should this be considered "just" an experimentally confirmed fact, or is is provable from Newton's laws? The following is a more precise context for this question...

Hello all, I have perused this forum for a while now. I've never signed up because I have nothing to offer you folks. I'm not evan an amateur, I'm just interested in physics. I'm a critical care / flight medic, so my understanding of physics is really, really, really limited. Although, I'm...

Homework Statement A resting hockey puck is hit with a force of 15.3 N. The frictional force slowing the puck down is 1.0 N. a) Find the net horizontal force acting on the puck while the stick is in contact with the puck. b) If the puck leaves the stick with a velocity of 45 m/s, how far will...

Im just reading this one example and i am stumped at this one step. (R\to C) \land (S \to C) \\ (\neg R\lor C) \land (\neg S \lor C) \ \ \ \ \ \textrm{by conditional law}\\ (\neg R\land \neg S) \lor C \ \ \ \ \textrm{by distributive law} I don't understand how it went from the second step to...

Homework Statement there are 2 formula of vont karman and prandit laws to find the friction factorfor rough pipe and smooth pipe , which formula should i use for this question? . P/ s : I'm asked to find the friction factor using the vont karman and prandit laws. Homework EquationsThe Attempt...

Homework Statement Wasnt able to upload file, therefore an external link https://drive.google.com/file/d/0B0FIIKckKOcKWFcxcmtJRVRXZTA/view?usp=drivesdk A force F= mg is applied on C, all pullies are frictionless and we need to find the reading of the spring balance, basically the tension...

Homework Statement Let ##x \in G## and ##a,b \in \mathbb{Z}^+## Prove that ##x^{a+b} = x^a x^b##. Homework EquationsThe Attempt at a Solution If I am not mistaken, we would have to do multiple induction on ##a## and ##b## for the statement/proposition ##P(a,b) : x^{a+b} = x^a x^b##. First we...

Hi, I'm currently making a three-body simulator and I'm trying to add the eccentricity to Kepler's Law to turn the circular orbits to more of a elliptical orbit? I'm using Newton's Law of Gravitational to plot the new positions. How would I add in the eccentricity to this equation? I'm...

Homework Statement All the surfaces shown in fig. are assumed to be frictionless. The block of mass m slides on the prism of mass M which in turn slides backwards on horizontal surface with acceleration of ao. Find the acceleration of smaller block with respect to prism. Homework...

Hi, I'm a frehshman in High school writing a paper about Isaac Newton. One of my paragraphs is about the laws of motion. I came across a tidbit of information - there are instances in which Newton's laws are not correct. One example I found was that, at speeds approaching that of light, an...

I find difficulties in identify the forces acting behind the acceleration of objects that are considered consequence of conservation principles (for istance of KE and angular momentum). I'll make an example to explain. The same string-mass system is linked to a rod. In case (a) a force pull the...

Must an initial state always be mapped onto exactly one final state and vice versa? Consider a slope that is shaped like a curvy "w". Releasing a ball from either end will result in the same final state where the ball is stationary at the highest point in the middle. So does it mean that...

Homework Statement Given a battery with voltage 35.7 V and 4 Resistors (Top left with resistance 2R, and the 3 others each with resistance R) where R = 507 Ohms, what current would an ideal ammeter read in its current position? (Diagram attached) Homework Equations Kirchoff's Laws: KCL and...

Homework Statement The picture has the problem question. OK. When the moon is at point B, the distance from the moon to the center of the planet is most nearly: A) (1/25) * rA B) (1/5) * rA C) (1/ sqrt(5) ) * rA D) rA E) sqrt(5) * rA. Homework Equations Newton's law of gravitation...

I think this may have been done before. So people are aware of the geometry of reflection. If I go beyond, I try to say that if light can pump electrons, it is absorbed, if it merely polarizes, it gives rise to an alternating dipole supposed to be polarizing the region around in all directions...

Homework Statement You tie a cord to a pail of water, and you swing the pail in a vertical circle of radius 0.700 m What minimum speed must you give the pail at the highest point of the circle if no water is to spill from it? Homework EquationsThe Attempt at a Solution I got the correct answer...

Homework Statement Consider the system shown in the figure (Figure 1) . Block A weighs 46.1 N and block B weighs 28.7 N . Once block B is set into downward motion, it descends at a constant speed. http://session.masteringphysics.com/problemAsset/1038576/6/YF-05-54.jpg A Calculate the...

< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown >[/color] Here is something that some one asked me, as their homework question, and it stumped me. A star is seen orbiting a black hole. The black hole's mass is 6.0E30 kg (approx, 3 solar...

Hi guys. I am planning to get 100 percent for my upcoming physics test in two days time. I am i grade 11. The test is based on Newtons 3 laws and universal law of gravitation. What are some of the best tips you can offer from your experience to help me achieve my goal?

I'm a little confused about the hamiltonian. Once you have the hamiltonian how can you find conserved quantities. I understand that if it has no explicit dependence on time then the hamiltonian itself is conserved, but how would you get specific conservation laws from this? Many thanks

Homework Statement After reading the forum stickies I'm not entirely sure where to put this question since it involves using math to solve a question, but is informally stated and isn't a book problem, either-I just started reading Fong's Elementary Quantum Mechanics, and in the first few...

Homework Statement (This is a long problem but I think the question is not hard.) Determining the star density from star counts is tough, but estimating counts from a density law is simpler. In practice, this method of fit-ting observed number counts to an assumed density law is becoming a...

Homework Statement We have an ordinary LRC circuit with inductance L, capacitance C and resistance R with an oscillating voltage with low frequency (U^e). Using the energy conservation law and Poynting's theorem, find the differential equation: $$L \frac{\partial ^2}{\partial t^2}I + R...

Hey, all. I've been studying Newton's Laws and I can't help but to feel a bit uneasy as I inspect them. From my point of view, they seem to be tautological. I'll refer to Newton's First Law as N1L, and similarly for the other two Right off the bat, I suppose I don't see any reason for N1L to...