Law Definition and 999 Threads

The answer key shows option D is correct. But I think option C is also correct. Which option is correct here?

Newton's Third Law: Action & Reaction His third law states that for every action (force) in nature there is an equal and opposite reaction. If object A exerts a force on object B, object B also exerts an equal and opposite force on object A. In other words, forces result from...

Boxer Bob punches a punch bag with a force of 430 N on the bag (the action force). The bag simultaneously exerts a force of 430N on Bob (the reaction force). We can see this force on Boxer Bob by the compression of his glove while it is in contact with the bag (assuming that the conditions...

Grateful if someone could explain why, if Newton's 2nd law says F=ma, I've read warnings and cautions in several physics books that mass times acceleration is not a force. Is it because the equals sign does not mean equals as in 2+2=4, perhaps?

ok, so usually one of the first equations in Diff Eq is F = -kx, which is the second order differential equation mx'' = -kx, where they give you the only general solution in the universe as Acoswt + Bsinwt. I was wondering, why can't you just separate the equation and get m∫x''/x = -∫kt'' which...

I tried using gauss law. This is how i set it up: I took a gaussian pill box of same area and very small length dx, the diagram is amplified for obvious reasons. Assuming theres a constant field in the yellow portion ##E_{1}## and a constant field ##E_{2}## in the green portion. I assume the...

See my attached working out. Thanks in advance [Images of attached PDF pasted into post by the Mentors]

I am reading "A First Course in General Relativity" by Bernard Schutz. In Chapter1 on Special Relativity Shutz writes: "... the principle of relativity is not at all a modern concept: it goes back all the way to Galileo's hypothesis that a body in a state of uniform motion remains in that...

my answer was B because wont it B be as its the normal reaction force? due to the newtons 3rd law?? correct answer is A...

The first image is for a conducting sheet (part of it anyway), the second is for a nonconducting sheet. Gauss' law seems to tell me that the electric field strength are different - they differ by a factor of two. Is this true? The charge enclosed in both of them are the same, and my intuition...

Here is a curve of induced emf against time. We know from Faraday's law that E = -N d(phi)dt and due to the negative sign, clearly E and d(phi)/dt must have opposite signs, i.e if E > 0it would not be possible for d(phi)dt > 0, as then -N d(phi)dt = E <0 , when we already defined E >0, clearly a...

r^2=(3.828*10^(26))/(4π*σ(5772)^4) It's diffrent from what I know...

In dire need of help, someone please explain the correct method for this, if its not possible what should i write in the conclusion for this?

Inverse square law would reduce the gravity from the parts of Earth that are farthest from our feet. It'll also reduce the gravity from Earth's center by a lesser amount, but would that be lesser enough so the gravity 20 kilometers under our feet is stronger than the core's gravity or even the...

For this problem, The solution is, However, why must we use absolute temperature for the ideal gas law (i.e why can we not use Celsius for T) Many thanks!

Hi! This project involves both mechanical and electrical elements, so I'm discussing it in this forum since I'm not sure which one it would fit better into. I'm working on an experiment in which I'm trying to measure the speed of sound through water. The approach is simple: I have a long...

I am not really sure which direction i am moving in with this solution

Assume that a closed system of cylindar filled with ideal gas consists of a movable piston.We know from the 1st law dQ=dU +dW. According to the 2nd law mechanical energy can be totally converted into heat energy but heat energy cannot be converted completely into mechanical energy.The question...

I am trying to Derive Malus's Law. My textbook says that an electric field as an amplitude ##E## before passing thought the polarizer and reduce to ##E_{trans} = E\cos\theta##. I am trying to understand why this occurs my considering a vertically polarized light passing though a polarizer that...

A. The two great cosmological discoveries of this century, Hubble's redshift and the cosmic microwave background, have made the Big Bang theory the most credible theory of the origin of the universe so far. B. The two great cosmological discoveries of this century, Hubble's law and the cosmic...

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In a recent article in Forbes, you could run into legal issues in using ChatGPT to further a business due to their indemnification clause...

I don't understand, can you calculate efficiency only using the temperature?

For whatever reason, I'm having a hard time conceptualizing this problem. I understand that the tangential components of all forces involved need to cancel out in order for the bead to be stationary. I also understand that there is a mgsinθ in the negative θ-hat direction. What I don't...

I truly am not sure. I assume it is that because everything has inertia, an a tendency to remain in a constant state of motion, when the clothes are quickly spun around they cannot remain in a constant state of motion (of either rest or constant velocity), but the water is "pushed"/spun out of...

What I did was just sub in the numbers and convert km to m. So (6.67E-10)(1000)(5.98E24)/(1,000,000+6.37E6)^2 * (1,000,000+6.37E6) So it's just (6.67E-10)(1000)(5.98E24)/(1,000,000+6.37E6). I thought this was a straightforward problem, but it seems that it is not. What am I missing?

https://www.intel.com/content/www/us/en/newsroom/news/gordon-moore-obituary.html R.I.P.

I am having difficulty understanding the information below. In the second line it states that F=0 as there is no external force on the system. However it later calculates acceleration of the rocket. How can Force=0 if there is acceleration? (This is the first time I have encountered the...

Is it possible, that one physics law is "Everything is in motion?" (since zero doesnt belong to nature)...if so, does that implies that black holes move?

TL;DR Summary: I approach a rocket acceleration problem using two approaches: F=d(m*v)/dt and F=ma. The resulting differential equations are different. What am I doing wrong? We have a ship with a mass-reaction rocket engine floating in space. The initial mass of the ship (including fuel) is...

I was wondering why energy of capacitor does not equal change in kinetic energy PLUS change in potential energy where potential energy is the change in the potential energy of the charges. I believe that should be so because energy conservation = change in kinetic energy plus change in potential...

The law states that in the same volume at the same pressure, the number of any gas is the same. It seems to me that this law does not apply, since each molecule of a different gas must have a different size, and between the molecules there will also be different sizes of pressure force, density...

Would the force (as predicted by Coulomb’s law) exerted on two charged particles q1 and q2, separated by distance r, and at rest relative to frame S change, if q1 and q2, began moving relative to S but we’re still at rest relative to each other?

Bragg's law is schematically shown on the picture: Two parallel and plane waves are shown which propagate towards the crystal. For plane waves, wave fronts are flat planes perpendicular to the wave propagation with infinite size. In reality, there are no plane waves. Nevertheless, they are...

Why is the length element (vector ds) perpendicular to the current? I though length element should be parallel to current. Would anybody be kind enough to help.

3 A+ 2 A = 7 A+ I I = -2A How the current can be in negative direction? If the sign if negative, doesn't it mean that the current will move towards the point P? Also If I am taking the 2A to be positive then Kirchhoff's law isn't satisfied as 5A≠7A

I have solved the question like this: Since Volume=Upthrust We need to find the upthrust and the volume V. To find the volume, we will submerge the block in the water and find the difference. To find the upthrust F, we will subtract the weight (finding the weight usinf newton-meter) from the...

Hello, I am studying probability and came across this theorem, it's the law of total probability with extra conditioning, I tried to work out a proof but couldn't ,does anyone know the proof for this : thanks!

Hello, I'm looking over some old school notes and re-learning some basic heat transfer. I have known Fourier's Law (1D: ##q = k\frac{dT}{dx}##) for a long time, but when I look at it now I find it strange that heat flux is inversely proportional to the length of the conductor. I would think...

And is that modified version of Coulomb's law "more accurate"? Edit: Same thing goes for Newtonian gravity, is "Newtonian gravity but ##F## converges as ##r\rightarrow##0" "more accurate"?

This problem is from MIT's module again. I have a doubt about Newton's Third Law. How is the normal and weight of the book not Newton's 3rd Law pairs? When the book is placed on the table, I imagine that the book's weight exerts a force on the table and the table exerts and equal and...

Why when you integrate the Biot-Savart Law do we not include limits of integration on the left-hand side of the equation (for the differential magnetic field)? Would the lower limit be 0 and the upper limit be B? How would you tell? Many thanks!

I am trying to figure out an intuitive understanding of how differential phase contrast (DPC) as a modality for measuring the phase shift as light passes through transparent samples. In a nutshell, DPC works by using either asymetric illumination or a split detector to standard compound...

My textbook gives the equation for Faraday's Law as ε=-(dΦB)/(dt) , the derivative of magnetic flux with respect to time. I have also seen Faraday's law expressed as ε= -(ΔΦB)/(Δt). Are these two forms equivalent? Thanks!

I am currently self-learning Ohm’s Law. My current approach is researching Ohm’s law and using multiple sources of information to gather relevant details about Ohm’s Law, like who discovered the laws and what the laws explain, and its concepts, like Voltage and Current. This approach is making...

Hi! For this problem, When Area 2 > Area 1, but not by much, is this phenomenon no longer called Torricelli's Law because the water is not approximately stationary at the top surface? What is this called now? Many thanks!

Hi I posted this differential equation to WolframAlpha https://www.wolframalpha.com/input?i2d=true&i=Power[\(40)Divide[a,1+b*cos\(40)y\(40)x\(41)\(41)]\(41),2]*y'\(40)x\(41)=c but no solution , " Standard computation time exceeded... Try again with Pro computation time " Should I ( buy and )...

hello i would like to understand something, i found the right answer but there is still something i don't understand. here is the figure and here is my correct solution what i don't understand is why F(3,Q) is 3kQ/r^2 i mean why is the 3? i only calculat the force between q3 and Q so why...