Newtonian mechanics covers the discussion of the movement of classical bodies under the influence of forces by making use of Newton’s three laws. For more general discussion of energy, momentum conservation etc., use classical-mechanics, for Newton’s description of gravity, use newtonian-gravity.

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How does length of the bar affect force on the muscles?

Fitness Model, Rob Riches, claims that doing bicep curls with Olympic bars is different than lifting with normal bars. Biceps have always been a favorite muscle group of mine to train, but ...
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Is Melancholia's orbit impossible?

In the 2011 movie Melancholia, a planet, also called Melancholia, enters the solar system and hits the Earth. I want to leave aside the (also unreasonable) aspect that planet "hides behind the Sun" ...
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What is the cause of the normal force? [duplicate]

I've been wondering, what causes the normal force to exist? In class the teacher never actually explains it, he just says "It has to be there because something has to counter gravity." While I ...
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Will a ball thrown straight up in a train land in same spot (in real world)?

I have a question that came up in a discussion with friends. If I throw a ball straight up in an enclosed train car moving with constant velocity, I believe the basic physics books say it will land ...
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How does the earth move?

My son who is 5 years old is asking me a question about how the earth moves around the sun. What answer should I give him?
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Galilean invariance of Lagrangian for non-relativistic free point particle?

In QFT, the Lagrangian density is explicitly constructed to be Lorentz-invariant from the beginning. However the Lagrangian $$L = \frac{1}{2} mv^2$$ for a non-relativistic free point particle is ...
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How would a newtons cradle act in zero gravity?

I imagine that the first ball would strike the rest as normal, but what would the last ball do, without gravity to swing it back?
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535 views

Where does the reaction to action come from?

Third Newton's law, $F_{1->2} = -F_{2->1}$ So, how does a body react with the same force that it's receiving from the acting body? Is it the electric interactions at the subatomic level? When ...
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Bouncing back of a ball [duplicate]

Possible Duplicate: Physics of simple collisions Let the unit vector along the positive x- axis be i and that along the Y-axis be j. Let us consider a rigid wall with the normal to the ...
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1answer
591 views

How do I determine the amount of lift needed to launch an object?

So as part of a video I'm working on, I'm trying to launch a 10kg table about 8m into the air. A machinist friend of mine has provided a solution that involves pneumatic cylinders and a pump to ...
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1answer
121 views

Different values of same physical quantity in time domain and space domain OR Physical explanation of Cauchy Schwarz result

I read this example in a popular math book I was browsing, and the author does not give any physical explanation. The example: Consider a rock falling freely under gravity. There are no viscous or ...
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An astronaut and a vengeful pole

Imagine an astronaut floating in free-space with no significant nearby gravitational influences. The astronaut takes an arbitrarily thin pole of uniform density with length $l$ and mass $m$, orients ...
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187 views

Spring oscillations and waves

Consider a block of mass $m$ attached to a spring. Let it oscillate at a frequency $f$. Now each part of the spring is in SHM. so this means a wave is propagating through this spring.bCan this wave be ...
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History of interpretation of Newton's first law

Nowadays it seems to be popular among physics educators to present Newton's first law as a definition of inertial frames and/or a statement that such frames exist. This is clearly a modern overlay. ...
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3 current loops with non-conservation of momentum, when one specifically considers SIGNs

Thought experiment I. Consider two loops of wire, 2 small dipoles B and C , with a common axis z (facing each other) and (say) 30 cm apart B to C. At the speed of light, information (including a ...
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1answer
332 views

Shaping a wire such that a bead sliding on it has exactly isochronous oscillations

Let a wire be shaped according to some even function $y=f(x)$, with $f'(0)=0$ and $f''(0)>0$, and let a bead of negligible size slide frictionlessly on the wire. Let the bead oscillate ...
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Can an object accelerate to infinite speed in FINITE time (Newtonian)?

Obviously this is impossible in relativity; however, if we ignore relativity and use only Newtonian mechanics, is this possible? How (or why not)?
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Simple friction formula for a car

I am making a 2D driving video game, and I would like to know the "simple" formula for calculating the friction force between the car and the road. I have read lots of friction diagrams involving ...
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719 views

How to get statics out of a dynamic force concept?

If one defines force as the time derivative of momentum, i.e. by $$ \vec{F}= \frac{d}{dt} \vec{p} $$ how can this include static forces? Is there a generally accepted way to argue in detail how ...
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Book suggestions for foundation of Newtonian Mechanics

I'm not looking for books which deal with the mathematical foundations of Newtonian mechanics. What I'm looking for are modern books which deal with conceptual foundations of Newtonian mechanics - by ...
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Is gecko-like friction Coulombic? What is the highest known Coulombic $\mu_s$ for any combination of surfaces?

Materials with large coefficients of static friction would be cool and useful. Rubber on rough surfaces typically has $\mu_s\sim1-2$. When people talk about examples with very high friction, often ...
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1answer
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How to calculate the exit velocity of a coil gun projectile?

First off, what quantities need to be factored in? Voltage and current through the coils, the magnetism of the projectile, the magnetic fields, etc.? Next, how would you calculate the speed of the ...
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2answers
328 views

Which direction does a pendulum swing in a car going through a ramp?

Suppose you have a car going clockwise around a ramp at constant speed. A pendulum is hanging from the rear view mirror. Does the pendulum swing outward or inward to the turn?
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Any interesting physics theroies/equations to be used in a video game? [closed]

I am designing a little game based on Newtons Graviational Law. Are there any theories that I can use to create games? thanks
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Could Jupiter's gravity destabilize Earth's artificial satellites over a long timescale?

Could Jupiter's gravity destabilize Earth's artificial satellites over a long timescale? After all, it can destabilize Mercury's orbit, and it can also destabilize orbits in the asteroid belt.
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Are orbits interior to Jupiter's orbit less stable than orbits exterior to Jupiter's orbit?

Or in other words, are there differences in average Lyapunov timescale between orbits interior to Jupiter and orbits exterior to Jupiter? I'm trying to answer a question at ...
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N particles, will there be any rotation after a period of time or everything will collapse

This is in context of classical Newtonian physics. Consider a system of n different point mass particles. Initially all are spread around on one plane. No particle possess any velocity to begin with. ...
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Rocket launch from a mountain

If we were to build a high speed rail up the side of a mountain like in some ScFi movies, what is the velocity needed at the point of living the mountain excluding angular momentum from earth’s ...
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Deriving Newton's Third Law from homogeneity of Space

I am following the first volume of the course of theoretical physics by Landau. So, whatever I say below mainly talks regarding the first 2 chapters of Landau and the approach of deriving Newton's ...
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257 views

Is this simulation following real physics?

I am trying to simulate a game in Box2D(Physics engine). The game that I am trying to simulate is very simple and can be found here: http://www.makaimedia.com/#/speartoss What I want to know is that, ...
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Can Vesta dominate the orbits of other asteroids?

I think I remember a talk where a professor said that Vesta is a particularly important asteroid because its gravity is strong enough to perturb other asteroids. In spite of Vesta's size, this effect ...
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Does it matter how you order your tug-of-war participants?

In a tug-of-war match today, my summer camp students were very concerned about putting the biggest people at the back of the rope. Is there any advantage to this strategy?
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Constrained particles under distance dependent force

This question is from the 1975 Canadian Association of Physicists Exam. No solutions are posted and I am quite lost on how to proceed with it. A particle is constrained to move along the x-axis of a ...
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Why do two bodies of different masses fall at the same rate (in the absence of air resistance)?

I'm far from being a physics expert and figured this would be a good place to ask a beginner question that has been confusing me for some time. According to Galileo, two bodies of different masses, ...
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a question on Lagrange's equation when the time derivative of the generalized co-ordinates is constant

Consider a system whose generalized co-ordinates are $q_i$ and is under the constraints $\dot{q_i} = K_i \forall i = 1,2,3,...$ where $K_i$ are constants. I have a problem in writing the Lagrange's ...
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Analyzing the motion of a ball rolling without slipping inside a hemispherical bowl

Consider a solid ball of radius $r$ and mass $m$ rolling without slipping in a hemispherical bowl of radius $R$ (simple back and forth motion). Now, I assume the oscillations are small and so the ...
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infinite grid of planets with newtonian gravity

Assuming only Newtonian gravity, suppose that the universe consists of an infinite number of uniform planets, uniformly distributed in a two-dimensional grid infinite in both directions and not moving ...
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Can someone explain the physics of a standing jump?

I would like to use something like a kinematic equation to know where the person will be in the jump at a given time. However since I think acceleration is not constant because of the jump force it ...
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463 views

Energy produced by a swing?

Please can someone help me with a equation for how much energy a person generates when swinging on a swing?
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Work done by gravitational field

To calculate the work done by a gravitational field, the equation is written as $$W=GMm(r_\text{initial}^{-2} - r_\text{final}^{-2})$$ Suppose a small mass has distance $R$ from a big mass. So here ...
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Why do we say that the earth moves around the sun?

In history we are taught that the Catholic Church was wrong, because the Sun does not move around the Earth, instead the Earth moves around the Sun. But then in physics we learn that movement is ...
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How does gravity affect bullets?

I read recently that if you hold a bullet in one hand and a pistol in the other, both hands at the same height, and subsequently fired the pistol at the same time as dropping the bullet, both bullets ...
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Wheel moving without sliding

Suppose we have a wheel moving on an horizontal surface, with constant velocity $v$, without sliding. This latter condition implies that the wheel rotates around its centre with angular speed $\omega ...
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Why are orbits elliptical?

Almost all of the orbits of planets and other celestial bodies are elliptical, not circular. Is this due to gravitational pull by other nearby massive bodies? If this was the case a two body system ...
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281 views

Action - Reaction pair, through photons

Here's an example to describe the issue Supossed a high power laser (eg a 100 kW laser, ie, electromagnetic weapons) is fired to a target, then it will receive energy and move. (and likely to burn or ...
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Torque required to turn a drum/barrel

I need to spec a motor to turn a mixing barrel. The barrel contains loose earth and can be filled to a maximum of 50% of its interior volume. It is a horizontal cylinder, and will rotate through its ...
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physics- momentum ( a space question) [closed]

An astronaut is conducting repairs on a satellite 50.0m from a space shuttle. Her mass is 120kg (including space suit) and she is using a 0.5kg spanner. She realises that she only has 5 minutes oxygen ...
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2answers
567 views

How are Euler's laws of motion applied to gyroscopes?

Euler's laws of motion for a distributed mass are: $$F = \frac{d}{dt} MV_{cm},\ N = \frac{d}{dt} L$$ $F$ are the sum of the external forces, $M$ the total mass, $V_{cm}$ the velocity of the centre ...
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How do you explain spinning tops to a nine year old?

Why don't spinning tops fall over? (The young scientist version) My nine year old son asked me this very question when playing with his "Battle Strikers" set. Having studied Physics myself, I am very ...
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Why don't we consider centrifugal force on a mass placed on earth?

Let us say a block of mass is placed on the surface of earth. Then while drawing the forces on that body, we say: Force $F = mg$ acting towards the center of Earth. Normal reaction $N$ offered by ...