Laws Definition and 1000 Threads

Homework Statement What is the acceleration of the masses as shown in the second attached image. m1 = 0.9kg, m2 = 1.6kg, and m3 = 2.4kg. (Assume the table is frictionless) Homework Equations \sumF=ma F_mg+FN = ma The Attempt at a Solution I figured everything up to the point...

Homework Statement T here are 2 blocks connected by a string, as shown in the first image attached. The smooth inclined surface makes an angle of 40 degrees with the horizontal, and the block on the incline has a mass m1 = 7.9kg. What is the mass of the hanging block m2 that will cause the...

Homework Statement A 60 kg driver gets into an empty taptap to start the day's work. The springs compress 0.02 m. What is the effective spring constant of the spring system in the taptap? using F=kx I got 2.94*10^4 Then After driving a portion of the route, the taptap is fully loaded with...

Find the current in I3 resistor by using kirchhoff's laws. problems: -when i try to use norton theorem to check for my answer and my answer is IN=2.855A=I3 but when i use kirchhoff's law i get I3=0.645A. -i don't know where is the problems...the current for norton theorem and kirchhoff's...

Do virtual particles break the conservation laws? Thanks

Homework Statement In the system shown all pulleys are light and smooth and all strings are light and inextensible. A block of mass m = 20 kg is attached to the movable pulley. A constant force, F, applied at the free end of the string, makes the point of application of force move down with...

I was checking online videos for lectures on kinematics and I watched one made by yale university but there was some part of it that I didn't understand when he talks about calculus derivation of Vf^2=Vi^2 + 2ax here is the video the derivation starts from about 1:08:45 I didn't understand...

I've been trying to organize my thoughts about conservation laws in GR, and so far I'm not having as much success as I'd like in bringing order to the whole topic. Maybe this is just the way GR is -- conservation laws don't play their usual central role, and their behavior varies on a...

1. Homework Statement A 10 kg block is subjected to two forces (10i + 20j) N and (6i - 8j) N. The magnitude of the resultant acceleration is (a) 2 (b) 3 (c) 4 (c) 5 2. Homework Equations F=ma 3. The Attempt at a Solution...

find x for y=5 y = -(((e^x)/(e^-x))/2) + ((e^x)/(e^(-3x)) all i did was a^m / a^n = a^m-n i get here y = -1/2(e^(2x)) + (e^(4x)) after this i get iffy and want to make sure i can do what i did. 5 = -1/2(e^(2x)) + (e^(4x)) ln|5|= -1/2(ln(e^2x)) + ln(e^4x) ln|5|= -1/2(2x) + 4x...

Thread split from this thread.[/color] Not true. The spray can is generating a constant force, not a constant power. As a result, the work done by the spray can depends on the distance it travels, and the power generated depends on the rate at which it is traveling. The farther the spray can...

Homework Statement This is not a HW, I am reviewing the basic material for my own use. Please prove the distributive laws. Homework Equations The Attempt at a Solution

How do you prove that the laws of physics are the same in all inertial frames of reference?

Hi everyone! I am really bad in physics so I need help in my assignments. My problem is what formula to use. Here's the problems. Homework Statement An electron (mass = 9.11 x 10-31 kg) leaves one end of a tv picture tube with zero (0) initial speed and travels in a straight line to the...

Hello everyone, i need help with these 2 question from physics. I am a year 11 physics student. Joey and Caitlin hang from two ends of a wire, looped through an ideal pulley. Joey has a mass of 75.0Kg, whilst Caitlin weighs 637N. a) calculate the tension of the wire? b) If Caitlin is...

Homework Statement A car can decelerate at -4.80m/s^2 without skidding when coming to rest on a level road. What would its deceleration be if the road were inclined at 13degrees uphill? Assume the same static friction coefficient. Homework Equations Ffr=µkFN The Attempt at a...

I have asked this question before, but couldn't get a satisfactory response. Let me make the problem more concise. We have a two particle system, i.e. two masses of mass m each joined together by a spring of spring constant k. A force F is applied to one of these particles in a direction...

I know what the definition of torque and angular momentum is. But I read in a few books that "Torque and angular momentum are not independent laws of nature, and have been derived from the more fundamental laws of Newton." The above simply means, that the rotational motion is just a...

Hi there, I have two simple physics questions. One day I was on the bus, and began to wonder why I kept getting thrown to the back every time the bus accelerated. Which one of Newton's laws can be applied to this?-if any. Another question is: When a rocket takes off, it applies a force in...

Homework Statement Hello. I'm starting to study thermo and I'm kind of confused. In this experiment: http://sci-toys.com/scitoys/scitoys/echem/echem2.html Note: I'm not talking about about the actual solar cell, I'm just talking about the heating up part (until the black layer...

Hello, I was drawing some curves on my computer when something appeared : it is possible to build trajectories that agree with all Kepler's laws with a very simple iterative process and very simple conditions. I wrote a paper to describe this fact and I built an online demonstrator to...

The "Laws" of physics In physics and math we often talk about the laws of nature. I have never liked to call these laws. My first diff EQ treacher felt the same. He liked to call them "really good aproximations". I perfer to think of them as equations that relate quanties in nature, or...

Homework Statement a) When a frame of reference undergoes acceleration/decelation (whatever,) what happens with regards to the Lorentz equations and Simple Relativity? How do the equations "change?" b) It is said that when twins move apart (or clocks move apart) that this is a...

For the following question: A magician pulls a tablecloth out from under some dishes. *How far do the dishes move during the .25 seconds it takes to pull out the tablecloth? The coefficient of kinetic friction between the cloth and the dishes is .12 I think I got the answer right by...

ok so I am working through a problem,got part way through and realized i couldn't remeber what to do with power rules,if someone could quickly remind me of the rules! the question is differentiate ƒ(x) = 1/x^3 Using if ƒ(x) = x^n then ƒ'(x) = nx^n-1 and the book answer given is ƒ(x) =...

Homework Statement a)If the mass of the crate is doubled but the initial velocity is not changed, what distance does the crate slide before stopping? Explain. b) If the initial velocity of the crate is doubled to 2vi but the mass is not changd, what distance does the crate slide before...

Homework Statement A crate pushed along the floor with velocity Vi slides a distance d after the pushing force is removed. a)If the mass of the crate is doubled but the initial velocity is not changed, what distance does the crate slide before stopping? Explain. b) If the initial...

As we all know, the air we breath is made up of appox... 78% Nitrogen ... 21% Oxygen ... and then traces of other random things. Lets consider that only the oxygen and nitrogen exist so that we neglect the other chemical traces. If I were to fire up a compressor that pumps outside air...

Homework Statement I understand how to determine the order of a rxn based on a series of experiments one divides one into another to obtain a ratio and then determines the power to which one is raised to determine the order. Typical data collected would be: Ex1 [A] .2 mol = Initial rate...

Homework Statement Hey. Is it correct to say that Ohm's Law, Kirchoff's Law and Thevenin Thereom are all related? Am I right in thinking that Ohms and Kirchoff's Law have been derived from Thevenin's Thereom? Just on very basic scale. Using the Thevenin's Thereom, I know that the ratio of the...

hi i just need a simple yet uncomplicated proof for (A UNION B)'S COMPLIMENTARY=A' INTERSECTION B'

In my layman opinion, the arguments last year (or the year before - context: DC gun law) that the second clause in the 2nd Amendment is not predicated upon the first, is at least grammatical overreach.

How come we say perpetual motion is not possible according to the laws of thermodynamics. Yet our universe is expanding faster and faster. How can we say nothing is faster than the speed on light but the universe expanding is? Keep it simple please.

Did that get your attention? Ok, so I'm mosty kidding, but I have a conundrum for you that exposes one of the weaknesses of the gas laws. Ready? In my astronomy class last quarter, we had to do a brief overview of physics, because physics isn't a pre-req, and some people had never taken...

!Logarithms and Index Laws help! Ive been trying to complete a revision sheet but it has logarithims and index laws, and i don't know how to do them. I've included a few of the hardest questions frome the revision sheet in the attachment. ...Look at attachment.... I've tried the...

"Natural Laws" and their domain of validity What is the philosophical justification for extending observed phenomena to "laws of nature". For example, Galileo dropped massive objects and saw that they fall at the same rate, but to then say that all massive objects fall at the same rate requires...

Homework Statement A table of mass 20kg is placed on the ground. A box of mass 3kg is placed on the table. Another box of mass 2kg is placed on the table, not in contact with the first box. Another box of mass 1 kg is placed on top of the 3kg box. The earth, table, and boxes are all at rest...

Homework Statement 1)The particle shown below is at rest, where F = 65.0 N, and θ = 33.1°. Find the magnitudes of F1 and F2. 2)Just after opening a parachute of negligible mass, a parachutist of mass 99.5 kg experiences an instantaneous upward acceleration of 1.09 m/s2. Find the force...

Homework Statement 8. A cylinder 1.00 m tall with an inside diameter of 0.120 m is used to hold propane gas (molar mass: 44.1 g.mol-1) for use in a barbeque. It is initially filled with a gas until the gauge pressure is 1.30 x 107 Pa and the temperature is 22.0⁰C. The temperature of the gas...

http://www.dailygalaxy.com/my_weblog/2010/05/do-newly-discovered-exploding-stars-point-to-new-laws-of-physics.html#more In the past decade, robotic telescopes have turned astronomers' attention to strange exploding stars that may point to new and unusual physics. An international team of...

Is my understanding correct: Charge is conserved at a vertex. So the charges of particles pointing in towards a vertex and the charges of particles pointing out must be equal. Alternatively: The sum of the charges at a vertex must be zero. So if this is correct, can someone explain the...

Homework Statement A railway engine pulls two carriages of equal mass with uniform acceleration. The tension in the coupling between the engine and the first carriage is T. Deduce the tension in the coupling between the first and second carriages. Homework Equations The Attempt at...

This month at PI there will be a 3 day workshop on the Laws of Nature. As outsiders, what can we learn? http://www.perimeterinstitute.ca/en/Events/Laws_of_Nature/Laws_of_Nature%3A_Their_Nature_and_Knowability/ Smolin and Unger have a book in the works about this (time and the laws of nature)...

Homework Statement The two blocks shown in the diagram are at rest on a horizontal surface when a force P is applied to block B. Blaocks A and B have masses 20kg and 35kg respectively. The coefficient of friction between the two blocks is 0.35 and between the horizontal surface and Block B is...

[SIZE="2"]Suppose, in a thermodynamic process, an amount Q of heat is given to the gas and an amount W of work is done by it. The total energy of the gas must increase by Q-W. As a result, the entire gas together with its container may start moving (systematic motion) or the internal energy...

Hey all, here's a question from one of my homework sets, any help is greatly appreciated.Homework Statement I've included a diagram of the situation. Basically, I have to find out how long it takes the block to reach the end of the ramp, the spring is massless, and friction is a factor in this...

1. What is the weight of an astronaut during lift off, if his actual weight is 750N and the acceleration of the craft is 5g's. The way I tried to solve it: F=ma F= 75(50) But answers are not matching, as the answer should be 4500N. I think I am missing something with that has to do with...

A bike starts from rest. It covers a distance of 1km from rest to rest. If the minimum time in which the bike covers the distance is 100s, the coefficient of friction between road and tyre = ? s = (1/2)at^2 no idea how to go about it.

Thank you ZapperZ for introducing these new peer-review papers. This one is of particular interest to me. I believe I may have some insight into this issue. In the normally constructed RC circuits using discrete components, the reactions of the individual components to signal frequency...

EDIT: My apologies if I started this thread in the wrong forum! Homework Statement Z = P.Q.R + P.R Where . = AND + = OR ~ = NOTHomework Equations (Commutative Law) A+B = B+A, A.B = B.A (Associate Law) (A+B)+C = A+(B+C), (A.B).C = A.(B.C) (Distributive Law) A(B+C) = AB+AC...