Newton Definition and 527 Threads

Hi All, Everyone knows so called "fictitious" forces, also known as "inertial" forces. They are forces felt by some mass point placed in a non-inertial frame. For example: a ball in a moving car or in a carousel. Maybe most intuitive fictitious forces are centrifugal forces, but there are also...

Using Newton's equation for gravity and assuming a corpuscular theory of light, one can calculate the angle that light would bend in a gravitational field. General relativity predicts a bend that is twice as large. In the Newtonian limit of GR (which includes weak gravity), does the GR...

Ok so I've asked my physics teacher and a statics teacher as well and I couldn't get a straight answer from either. So here's my questions... Correct me if I'm wrong, but isn't the gram a unit of mass? Not weight? I thought that for mass to become a unit of weight, it has to have to...

This question concerns inertial frames. I am aware that an inertial frame is one that is not accelerating. I am aware of an alternative definition: it is one on which no forces are applied. (Yes, they are the same thing.) I am also aware of the d'Alembert "forces" that appear when a frame is...

I recently started reading Feynmans book QED. There are a couple of questions I have regarding his theory on the percentage of light that is reflected of two surfaces of glass. My question is as follows, A piece of glass in fact has four surfaces. The front of the glass the back side of...

I was surprised recently to learn that one of the reasons both Newton and Einstein were so revolutionary was that they performed a neat mathematical trick. For Newton, it was the mathematical derivation of Kepler's laws from Newton's laws of gravitation and motion. For Einstein, it was the...

Task Use the Bisection, Newton, and Secant methods to solve (to at least 8 signicant figures) the equation sin(x) = 0.98 cos(2x2) over the interval [0, 2.5], in radiant units. For the Newton method, try with several different initial guesses including x0 = 1. With the Secant method, use the same...

I did some googling but only found nothing to answer my question. How did Newton come up with this formula, literally/physically? Did he have chunks of stuff and moved them around, then logged various results. Then maybe he played around with various formulas and saw which fit the data?

Hello, To ensconce this question properly, we know that some of the major contributions to the discipline of rigid body and classical particle dynamics came from: Newton, Euler, Hamilton, Lagrange and so on... (no need to suggest other western names right now - I am aware of them). However I...

If I have a laboratory water bath (circulated for homogeneity in temp) that I will monitor over a period of time (probably 2 scenarios, an hour at most, and then at least 24 hours or longer), how do I quantify the effect of atmospheric pressure in our test lab. What I will do is use an...

Homework Statement The Lagrangian density for the ##h=h^{00}## term of the Einstein gravity tensor can be simplified to: $$L=-\frac{1}{2}h\Box h + (M_p)^ah^2\Box h - (M_p)^b h T$$ The equations of motion following from this Lagrangian looks roughly like (I didn't calculate this, they are given...

I am wondering if anyone knows of a good resource to see Newtons first law in action. For example, a block being pulled by increasing force until it moves?

Homework Statement I have a rope held by a hook, which is attached to the ceiling by a chain (with an angle theta), in one side, the rope (with an angle alpha) is attached to a a wall, in the other side, the rope is carrying an anvil of 110 Kg mass in vertical position. What is the tension in...

In most cases, we know why things happen. Protons can stick with each other because of the strong nuclear force. There's all kinds of forces and we know mostly about why they occur and how they are transmitted. But I don't understand gravity. Why do objects with mass attract each other ? I know...

Homework Statement Suppose we have: ## f(x) = x^2 - b ## ## b > 0 ## ## x_0 = b ## And a sequence is defined by: ## x_{i+1} = x_i - \frac{f(x_i)}{f'(x_i) } ## prove ## \forall i \in N ( x_i > 0 ) ## Homework Equations The Attempt at a Solution a)Here I tried solving for ## x_1 ## as...

Hi, i have a question. I need to know how much Newton it takes to separate 2 magnets or a magnet from a from a piece of metal. I've bought a spring scale that measures max 50 gram, so very accurate. Now what if i attach the scale to the magnet and i pull it horizontally just enough to...

Homework Statement The problem relates to the subject of torque and angular momentum: A man of mass ## M ## stands on a railroad car that is rounding an unbanked turn of radius R at speed v. His center of mass is height ## L ## above the car, and his feet are distance ## d ## apart. The man is...

Hello, I understand that Newton's laws of motion can explain how a hummingbird is able to hover in front of flowers. There is one question I have in particular, which is, Is the lift generated by the wings of the bird and its weight force an example of a pair of Newton's third law forces? They...

Hi, I would like to ask you what happens when you change (gradually) a mass of one body in a classical two-body-problem. May it lead to such results? Many thanks. Flor

I'm sizing a shock absorber at the moment for a project and I have accelerometer readings of a road going over bumps (3 gs). I have already applied gravity to the load to get my 5.5kN If the weight of the static load at that point is 5.5kN would it be safe to say the spring needs to be sized to...

Hi, I had a thought recently which gave rise to a rather interesting query. A helicopter works and is able to fly due to Newton's third law of motion. The propellers rotate at a high speed and exert a force on the air beneath them. By N3L, the air therefore exerts an upwards force on the...

Imagine, There's a ball in deep space traveling with a constant velocity of 25m/s and is having mass 25kg. Now as I said, ball is traveling with a constant velocity that simply means acceleration=0 and now if we calculate the force with F=ma we will end up with 0. But if that ball collide with a...

Homework Statement A total of 31 bright and 31 dark Newton's rings (not counting the dark spot at the center) are observed when 550-nm light falls normally on a planoconvex lens resting on a flat glass surface. How much thicker is the center than the edges? Homework Equations 2t = mλ 2t =...

Hi! I am currently working on a project that includes rotating a water-filled container. The container is NOT spinning about its vertical axis, but about the vertical axis of the rotating disc. I am aware that the surface shape of water in a rotating bucket takes the shape of a parabola when it...

I am not a teacher, but I have made an interesting observation regarding classical mechanics education. It is surprisingly common that even students at academic level do not seem to fully understand Newton's third law (action and reaction) and confuse it with Newton's second law...

Hi, This a Classical Mechanics problem I've been trying to solve for a few days now. I cannot use Lagrangian or Hamiltonian formulation, it must be solved using classical Newtonian formulation. One must determine the equations of movement of the particle in cartesian, spherical and cylindrical...

Homework Statement A sled of mass m is given a kick on a frozen pond. The kick imparts to it an initial speed of 2.20 m/s. The coefficient of kinetic friction between sled and ice is 0.150. Use energy considerations to find the distance the sled moves before it stops Homework Equations...

Homework Statement Homework Equations Friction Force = normal force * static coefficient for friction Fnet = ma The Attempt at a Solution So i drew the free-body diagrams for both the objects...[/B] Im trying to figure out the tension in the 2nd free body diagram and i know that it's...

Experts tell me that: "At average gravity on Earth (conventionally, g = 9.80665 m/s2), a kilogram mass exerts a force of about 9.8 Newtons. An average-sized apple exerts about one Newton of force, which we measure as the apple's weight.. After one second, you're falling 9.8 m/s.. .. falling from...

These are conceptual questions, and i just want to really understand why the answer is the answer! 1. Homework Statement 1) A force acts to push two boxes, box 1 and box 2, across a floor (assume for this problem that friction is negligible). The two boxes are stacked such that the force...

My son is taking a chemistry class in high school, and he was telling me this morning that their teacher had taught them there was some kind of fundamental distinction between scientific laws and theories. He said the teacher had told them that laws are just fundamental regularities observed in...

So I was curious about something. Having a flat tire today and having to change my tire made me wonder. I understand torque and force are 2 different things though related they have separate meanings. So my question is if I have a 2 foot tire iron and I am torquing my nuts. Let's say they...

Hello Everyone ! I am interesting to find descriptions of the series of experiments that Newton made for determining the laws of motion. In English of course.

In the picture above, there are three balls in separated small elevators. Elevator A lifts the ball upwards, elevator B stays still, elevator C moves the ball downwards, all in constant speed. (And this is a model, a simplification of the reality, we assume no other forces on the balls other...

ince f=ma, and we derive whatever the force it takes to accelerate a specific mass at a specific acceleration as a unit of force. I understand this ratio of actual force will always be the same in the entire universe but is there a reason why for example 1kg accelerated a 1m/s^2=1 N which is...

Homework Statement A plug with a given mass is placed in the end of a horizontal pipe to hold water at a given pressure behind it. Is there any way to calculate how far this plug would move in the x-axis if it suddenly lost it's grip against the pipe wall, and it was situated a given height...

General physics question regarding force and gravity. Hypothetically speaking if every piece of mass weighed double. If something that weighed 1 Pound is now 2 pounds. If you weigh 100 pounds now you weigh 200 pounds . Assume gravity is still 9.8ms/sq. and you never experience gravity any...

I have always wanted to read the textbooks in the thread title. But their styld is so old. Does someone know of any "middle of the road" textbooks? By that, I mean: books that basically teach what these two men wrote, but, perhaps with updated language, or some really-not-essential stuff...

I was doing some practice problems to become more familiar with the Center of Mass Velocity and I came across this one from (Noted in the picture) Engineering at Illinois, that relates the velocity of the center of mass in both the x and y direction, however I don't quit understand the answer...

Many scientists are regarded as geniuses based on their work (Einstein, Newton, etc). What is it about their work that is so clever that few others could have done it?

An interesting subject that was getting off topic from another thread… https://www.physicsforums.com/threads/does-gravitational-time-dilation-imply-spacetime-curvature.919181/ Note: Newton was not alone in this. Rene Descartes stated that the problem with relative motion is that every particle...

Hi. I’m trying to build something and having very little basic physics am having to try and learn as I go along. Today I spoke to a company that makes damping units and I was asked how much force in Newton meters would be applied to the unit at the top speed. It’s a small cart weighing 70Kg and...

"Ghosts of Departed Quantities" And a host of ones own deity?

So I understand the relationship between mass x acceleration=force but all that relationship tells me is "Whatever the force is to accelerate a given mass at a specific unit of acceleration = units of force, and we just accept whatever the unit of force is. example 1/ms² x 1 kg mass = 1 N...

Hey guy! I used google but it didn't help so can you guy pleas tell me how Mr.Newton explained his law please. Thank!

Homework Statement [/B] My physics teacher - "You may like this question, its very structured" Calculate the distance a slate tile falls from a roof The roof is angled at an angle 30 degrees. mass of slate tile is 0.8kg The length of the roof is L=6m The height of the roof above the ground is...

There's a pendulum attached to a car accelerating with ##A##. I know I can find it's time period using the "effective" g method, but I want to find it from first principles. My attempt: ##tan\theta = A/g## Now I displace it by ##\alpha## giving ##mgsin(\theta+\alpha)-mAcos(\theta+\alpha) = ma##...

We were asked to do an experiment where we had to prove the equation: T2=(4π2m)/Mgr Where M is the mass of the mass stack in kg (0.3kg), m is the mass of the rubber bung in kg (0.0226kg), T is the time taken for one rotation in seconds, r is the horizontal radius of rotation in meters, and g is...

1) the problem I understand Newton's method and I was able to find all the real roots of the function.However, I don't understand how to find the complex roots. I know that z=x+yi, and that I can plug in z for the formula. However I, don't know how to change the function (...

Hey guys, I'm new to the forum and I have a question that has stumped several of the professors at my school. My idea is to use an electric motor with a solid rocket engine on a thrust stand to spin the exit cone. The concept would make use of centripetal force to increase the pressure of...