Newton Definition and 525 Threads

This model describes the gravitational field of a non-rotating, spherically symmetric body—without spin effects such as centrifugal acceleration or equatorial bulging. The Construction Process • Begin with Newton’s law of universal gravitation and a sphere of radius R with constant density d. •...

Title: Reframing Light Bending Using Density Instead of Radius I’ve been exploring an alternative way to express gravitational light bending, starting from the classical general relativity approximation: θ = (4 * G * M) / (r * c²) Instead of using radius r, I substituted it using the density...

Title: Gravity Proportional to Mass over Surface Area — A Dimensional Approximation I derived an approximation for surface gravity using the gravitational constant and surface area: g ≈ (4π G M) / A 🔍 What Each Symbol Means: • g: Surface gravity — the acceleration due to gravity at the...

I am Sojeong Ki from South Korea. I am studying The Theoretical Minimum by Leonard Susskind, and I joined this community to ask questions and receive answers to ensure that I am understanding the material correctly. And the part I am currently studying is Newtonian classical mechanics. I look...

Is it okay to assume that the Newtonian formula $$ F = G \ \dfrac{ m_{_1} m_{_2} }{d^2} $$ is itself a theory of quantum gravity ?

(a) ##T_{a}(t)=t+5## (b) $$\frac{dT}{dt}=-k(T-T_{a}(t))$$ $$\frac{dT}{dt}=-k(T-t-5)$$ $$\frac{dT}{dt}=-kT+kt+5k$$ Is my working for (a) and (b) so far correct? Thanks

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?

Assume there are two objects on the same surface, one is a cube and the other is a sphere. Both objects have the same mass m. The required applied force to the center of mass of the cube for it to start sliding should be equal to static friction force: μs⋅m⋅g. But what is the required applied...

Which exactly year Newton first time write about calculus, 1664, 1665 or 1666? I find three years circles in many sources, 1664, 1665 and 1666 , do yo maybe know some thrusted source where we can find correct information? Here is 1665...

Hi, How to convert 51065 foot pound per second to Newtons, not Newtons meter per second?

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...

I've started reading the Principia and have been trying to follow along with the examples. Unfortunately, I got stuck almost immediately. This example is from 'Axioms, or laws of motion', Law III, Corollary II. It is based on the following picture (everything in red is my addition): The text...

The answer is 441N instead of 883N, but why? can anyone help?

I'm having problem in drawing the distributed load (weight per foot) for the inclined beam as it shows. should it be rectangular? if so shouldn't the distributed load be vertical down as the resultant weight at the centroid (W) please help me understand how to draw the free body diagram for this...

TL;DR Summary: . An electrone moves in a magnetic field ##B(\vec r)=g \frac {\vec r}{|\vec r|^3}##. Why does the conservation of the quantity $$\vec J=\vec r \times\vec p +eg\frac {\vec r}{|\vec r|}$$ mean that the motion is on the surface of a cone?

https://www.scientificamerican.com/article/mistranslation-of-newtons-first-law-discovered-after-nearly-300-years/

I have an assignment in physics and I can't understand the difference between the 2 questions. That's the question A skier with mass m=70 kg stands on a ramp of height h. At the foot of the ramp, there is a loop with a radius of r=15 m. When entering the ramp, the speed is v1=0 m/s. a) For...

I'm finding the uncertainty of k, given that each temperature has an uncertainty of +/- 0.5 degress.

For this, Does someone please know how do we derive equation 9.9 from 9.8? Do we take the limits as t approach's zero for both sides? Why not take limit as momentum goes to zero? Many thanks!

I’m analysing the gravitational relationships between different mass astronomical bodies and am getting sick of having to individually google and document these. Are there data sets out there that list pairs/sets of objects which includes their mass and distance from each other? Including...

It asked for a snappy title so don’t judge! I’m here for the physics not the BS. And I’ve checked my Dunning-Krugerness & Confirmation Bias at the door! In a way I’ve always been fascinated by physics and the biggest of questions but recently I thought I’d jump in and actually participate as...

I'm stuck to understand 3 laws of Newton. It doesn't make sense to me. 1. Suppose the case when a person stay in a rest vehicle.When we accelerate the car the person still at rest so the person has to move to the tail of the vehicle cause his intertia of staying rest. If we decrese the...

regarding the last question. I know that resistance is a negative force because it goes in the opposite direction to the movement of the boat. So whenever, I want to apply Newton's 2nd law of motion: the sum of forces = m a I should write - F resit = m.a. However, they have considered the...

I would just like to get a perspective on how much is an x amount of Newtons, like in real world examples. I know everyone says 100N is about equal to the force of a 10kg object being set on you, but this example really only gives perspective on downwards force. For example I calculated the...

Many tutorials that explain the weak principle of equivalence (Galileo, Newton) do not clearly state whether the body is affected by the force of inertia during free fall as a result of the gravitational acceleration of the body. In other words, the question is whether, during the free fall of a...

Hello everyone, my question is, if there is a case, where you can't you Langrange (1 or 2) but only Newton to solve the equation of motion? My guess is, that it might be, when we have no restrictions at all, so a totally free motion. Does anybody know?

I thought about using the snell’s law because it involves different refractive index but I have no idea why the wavelength would be affected by the snell’s law. I thought that maybe if I found the frequency I might be able to get the wavelength but, I don’t know which formula I should use. I...

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I was wondering to read this book to get a better understanding of the classical world. I want to know what things are there that I can learn in this book? Is it worth it? Is it tough? Should I read it or it will be covered in undergraduate and graduate level of physics?

https://www.khanacademy.org/science/physics/forces-Newtons-laws/Newtons-laws-of-motion/a/what-is-Newtons-second-law How do I find the horizontal right components force? It states it is 22 N but there is no reason that the left horizontal component is the same as the right. I thought the...

When Newton developed his law of universal gravitation, why would he use distance squared d², instead of 4/3πr³ as the field would expand in a sphere around the body?

The law of action and reaction is the explanation that I see everywhere. But I can't find anywhere what exactly pushes the balloon in the opposite direction as the air coming out. Air molecules come out to where pressure is less. What exactly moves the rubber balloon in the opposite direction...

I am speaking here not of the modern definitions (like a 1st Newton law as a definition of an inertial reference frame), but rather on the way the 1st law was formulated in the time of Newton. That is, it's obvious that the 1st Newton law in its original formulation is a corollary of the 2nd...

Hey! :giggle: Question 1 : Let $g(x)-=x-x^3$. The point $x=0$ is a fixed point for $g$. Show that if $x^{\star}$ is a fixed point of $g$, $g(x^{\star})=x^{\star}$, then $x^{\star}=0$. If $(x_k)$ the sequence $x_{k+1}=g(x_k)$, $k=0,1,2,\ldots$ show that if $0>x_0>-1$ then $(x_k)$ is...

Hey! 😊 I have calculated an approximation to $\frac{\pi}{2}$ using Newton's method on $f(x)=\cos (x)$ with starting value $1$. After 2 iterations we get $1,5707$. Which conditions does the starting point has to satisfy so that the convergence of the sequence of the Newton iterations to...

Summary:: What does I need to consider in order to get the right spring? Hello. I need a compression spring that require 10 lbs of force in order to be compressed 1cm. The springs outer diameter (De) has to be 1cm. The spring will be made out of piano wire. Which values of specification does...

Quantum mechanics has argued for years that space is not a vacuum. Arguments attempting to brush aside quantum mechanics vacuum theory claiming, it's 'just a quantum mathematical theory' can now put to rest. In this article, laboratory experimentation demonstrates that the Casimir Effect can...

Let's say you have two masses on either side of a spring. Mass 1 is connected to the end of a spring. The spring itself has no mass. Mass 2 is free in space. So you have: [M1]-[spring] [M2]So it's more descriptive, I'll name the variables like you might in programming. Let's define...

Hello, I am having difficulty in translating the univariate Newton's approximation {Xn = Xn-1 - [ f(Xn-1) / f'(Xn-1)]} into the multidimensional case. My multidimensional equation system is y = F.x where y and x are (nx1) column vectors and the coefficients matrix F is (nxn), so that (nx1) =...

Is concept of inertial vs non inertial frame inveted in Einsten theory of relativity or Newton knows that we can see on same object from different perspective? (Newton set 3 laws for inertial frame,so did he knew for realitivtiy when view object form different perspective/frame and did he...

Hi ... air resistance is the reason that objects of different mass fall to Earth at different speeds. In a vacuum all objects fall to Earth at the same rate regardless of mass. OK - I get it but all the experiments that illustrate this tend to rely on tall buildings or massive vacuum chambers...

Hello guys, The third law says: "For every action, there is an equal and opposite reaction. The statement means that in every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second...

Through the research that I conducted is that I wasn't able to find actual supporting answer to this question. I struggle with Physics and math and because of Coronavirus my school has shut down meaning I don't have access to my teachers or tutor. The main line that i am thinking is that if it...

α is the second derivative of angle and w is the first derivative In the free body diagrams the only force on A is the normal force since it is only constrained not to move vertically. Have I drawn the free body diagram and kinetic diagram correctly? By relating the accelerations of the...

I'm having quite a bit of a problem with this one. I've managed to figure out that ##T_0 = 0##. However, not knowing what ##q(t)## is bothers me, although it seems that I could theoretically solve the problem without knowing it. For ##t>t_1##, integration by parts gives me ##T = Ce^{-t/10}##...

If Newton II is defined as ##\sum F = \dot{p}## and ##p = mv##, why do we consider Newton I as a separate law for cases where ##\sum F = 0##? Is Newton I really independent of Newton II?

Is it appropriate to say that within classical physics the general form of Newton II is the Cauchy momentum equation? This equation applies to an arbitrary continuum body. Therefore it is more general than the common form of Newton II which applies basically to point masses and centers of mass...

Let T be the tension in the string, a be the acceleration of mass 2m, 2a be the acceleration of mass m T = (m) (2a) ---eq(1) The mass 3m will come down with acceleration a’ = (a+2a)/2 = 3a/2 3mg - 2T = 3m . 3a/2 from equation 1 3mg - 2(2ma) = 3m . 3a/2 thus a = 6/17g thus acceleration of 3m...