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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What does Feynman mean when he says that $F=ma$ is not exact?

Chapter 12-2 in Feynman Lectures Vol. 1 states: In fact the law, $F=ma$ is not exactly true; if it were a definition we should have to say that it is always true; but it is not ... First, ...
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Does ABS shorten stopping distance of a car?

ABS, from German Antiblockiersystem, is a device put in almost every new automobile. The web has lots of explanations about the system, how it works, but I don't understand how it shortens the way of ...
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What is the cause of centripetal/centrifugal force?

What is the cause of centripetal/centrifugal force? When an object of mass $m$ is moved in a circular orbit, it experiences a centrifugal force radially away from the center. What is the cause of this ...
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Put a bullet into orbit around the moon

While I was watching this beautiful video, the absence of air friction pushed me to ask myself: While standing on the surface of the moon, what is the initial velocity by which you can fire a bullet ...
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Would a bicycle stay upright if moving on a treadmill and why?

I suspect not, because moving forward (or backwards for that matter) is an important part, but I would like to confirm. UPDATE: Clearly it's possible ...
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How long would a lever have to be to move the planet Earth?

Give me a lever long enough and a fulcrum on which to place it, and I shall move the world. -Archimedes How long would that lever have to be? That is to say, how long a lever ...
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Is the gravitational potential of a planet in orbit always equal to minus the squared velocity?

Say a planet (mass $m$) is orbiting a star (mass $M$) in a perfect circle, so it is in circular motion. $F=ma$ and the gravitational force between two masses $F=\frac{GMm}{r^2}$ so ...
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In a universe where the speed of light is infinite, are relativistic models and Newtonian models equivalent?

Take our universe. Observations are consistent with relativity, but not consistent with Newtonian mechanics. Assume that our current (relativistic) model of gravitation is correct. Now increase $c$ ...
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How is distance between sun and earth calculated?

How has the distance between sun and earth been calculated by scientists? and size of sun? Thanks,
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Is acceleration an average?

Background I'm new to physics and math. I stopped studying both of them in high-school, and I wish I hadn't. I'm pursuing study in both topics for personal interest. Today, I'm learning about ...
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What is the period of a physical pendulum without using small-angle approximation?

What is the expression for the period of a physical pendulum without the $\sin\theta\approx\theta$ approximation? i.e. a pendulum described by this equation: $$ mgd\sin(\theta)=-I\ddot\theta $$ ...
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What is the force on the arms in a pushup?

What force do the arms have to generate to do a pushup? Let us look a this simplified model: The body can be represented by the green plank of mass B. Its angle to the ground is $\theta$. This ...
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Dynamics of counter-rotating flywheels

I've wondered about this for ages. If we create a pair of flywheels that rotate in the opposite direction with the same angular momentum, but are co-located and have the same mass and inertial moment ...
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How fast do you have to spin an egg to have it standing?

If you take a hardboiled egg and put it on a table and start to spin it, if you spin it fast enough it will start to spin in an upright position. What is the angular velocity needed for this ...
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How can a planet gravitationally capture objects?

I would expect that any asteroid or other object originating far away but passing near a planet would pick up speed and energy as it approaches, but unless it comes into contact with the atmosphere ...
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Intuitive explanation of why orbits are closed?

Yesterday my brother asked me how orbits work. Suppose for the sake of the question that you are trying to put a rocket in orbit around the Earth. I explained that orbiting is essentially being in ...
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What makes a wrist-energized gyroscope rotate faster?

I'm considering a wrist-energized gyroscope, shown below (after my daughter let it fall and it broke open). That one was sold as Roller Ball, but variants are known as Powerball, DynaBee, Dynaball, ...
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D'Alembert's Principle: Necesssity of virtual displacements

Why is the D'Alembert's Principle $$\sum_{i} ( {F}_{i} - m_i \bf{a}_i )\cdot \delta \bf r_i = 0$$ stated in terms of "virtual" displacements instead of actual displacements? Why is it so necessary ...
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Recommendations for good Newtonian mechanics and kinematics books

What are some good books for learning the concepts of Kinematics, Newton laws, 2D Motion of Object etc.?
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If it was possible to dig a hole that went from one side of the Earth to the other…

...And you jumped in. What would happen when you got to the middle of the Earth? Would you gradually slow down, until you got to the middle and once you were in middle would every direction feel like ...
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Why does tossing a coin in a train and on a train differ?

Suppose that I am inside of a moving train. I have a coin in my hand and I am standing still. If I toss this coin straight up, it will fall back into my hand. Now, suppose that I am on that moving ...
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What creates the chaotic motion on a double pendulum?

As we know, The double pendulum has a chaotic motion. But, why is this? I mean, the mass of the two pendulums are the same and they have the same length. But, what makes its motion random? I'm just ...
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Huge buildings affect Earth's rotation?

Does constructing huge buildings affect the rotation of the Earth, similar to skater whose angular rotation increases when her arms are closed comparatively than open?
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How much more efficient is a road bike than a mountain bike? [closed]

What would be a good estimate on the difference of efficiency between a road bike and a mountain bike? A number of links cite all the usual reasons: thinner tires, better aerodynamics... But I'm ...
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How does Newtonian mechanics explain why orbiting objects do not fall to the object they are orbiting?

The force of gravity is constantly being applied to an orbiting object. And therefore the object is constantly accelerating. Why doesn't gravity eventually "win" over the object's momentum, like a ...
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Non-Constant Acceleration due to Gravity

Recently, I had the first physics lab for my university physics course. This lab was fairly simple, as we were merely using a computer and a distance sensor to graph the position, velocity, and ...
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What causes a soccer ball to follow a curved path?

Soccer players kick the ball in a linear kick, though you find it to turn sideways, not even in one direction. Just mid air it changes that curve's direction. Any physical explanation? Maybe this ...
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Explanation that air drag is proportional to speed or square speed?

A falling object with no initial velocity with mass $m$ is influenced by a gravitational force $g$ and the drag (air resistance) which is proportional to the object's speed. By Newton´s laws this can ...
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What does it mean when physical theories are inconsistent?

I am hoping that someone can explain in layman terms why Newtonian mechanics and Maxwell's equations are inconsistent. Wikipedia says that this inconsistency is what led to the development of ...
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A fly in an accelerating car

A fly is flying around in a car, the fly never touches any surface in the car only fly’s around in the air inside the car. The car accelerates. does the fly slam in to the rear window. or does the fly ...
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Why is a book on a table not an example of Newton's third law?

My textbook explains Newton's Third Law like this: If an object A exterts a force on object B, then object B exerts an equal but opposite force on object A It then says: Newton's 3rd law ...
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How do you explain Kepler's third law in general terms without complex math?

I understand the first law-elliptical orbits, and the second-equal area in same time, but I need help with the third one. Note that I am not in an AP course or taking calculus at the moment so simple ...
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Where does the extra equation come from to determine the forces from an object on a table?

I have a question about basic statics but somehow I cannot manage to find the answer on my own (btw, this is not a homework. It's been so many years since school for me...). The problem is very ...
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What's the exact gravitational force between spherically symmetric masses?

Consider spherical symmetric$^1$ masses of radii $R_1$ and $R_2$, with spherical symmetric density distributions $\rho_1(r_1)$ and $\rho_2(r_2)$, and with a distance between the centers of the spheres ...
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Camp Fire Crackle

I was sitting around the camp fire and there was a periodic sound of cracking and pieces of the burning wood flew off. My question is what is the mechanism for the cracking of the wood? I was thinking ...
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Static Friction - Only thing that can accelerate a train?

I'm a computer programmer that never studied physics in school and now it's coming back to bite me a bit in some of the stuff I'm being asked to program. I'm trying to self study some physics and ...
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How does escape velocity relate to energy and speed?

I have several confusions regarding escape velocity. I am sure I am missing something(s) obvious or maybe I am taught wrong. Lets say we throw an object of any mass at exactly escape velocity of ...
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Which force is responsible for victory in tug of war?

I'm confused: In a tug of war game on rough ground who will win? The one who applies greater force on the rope or the one who applies greater force on ground?
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Slinky base does not immediately fall due to gravity

Why does the base of this slinky not fall immediately to gravity? My guess is tension in the springs is a force > mass*gravity but even then it is dumbfounding.
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Intuitive meaning of Newton (units)

Is there any intuitive reasoning behind why the units of a "Newton" is $kg \frac{m}{s^{2}}$ and how it represents force? I always wanted to understand why objects of different mass fall at the same ...
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Why didn't Newton just propose the 2nd Law and leave it at that?

Why didn't Newton just propose the 2nd Law ($F=\dot{p}$) and leave it at that? The 2nd Law implicitly contains the first, doesn't it? If so, it seems he wasn't following his own Rule #1 of Book 3 of ...
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What in Newton's three laws of motion is original and not a paraphrasing of his predecessors?

The three laws are: First law: The velocity of a body remains constant unless the body is acted upon by an external force. Second law: The acceleration a of a body is parallel[disambiguation needed ...
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Effect of the tail of the cat in the falling cat problem

To explain why a falling cat can turn by 180 degree without external torque and without violation of the conservation of angular momentum, one usually models the cat as two cylinders as in ...
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Dependence of Friction on Area

Is friction really independent of area? The friction force, $f_s = \mu_s N$. The equation says that friction only depends on the normal force, which is $ N = W = mg$, and nature of sliding surface, ...
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What is the maximum efficiency of a trebuchet?

Using purely gravitational potential energy, what is the highest efficiency one can achieve with a trebuchet counter-weight type of machine? Efficiency defined here as transformation of potential ...
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Block on a block problem, with friction

Consider two blocks, one on top of the other on a frictionless table, with masses $m_1$ and $m_2$ respectively. There is appreciable friction between the blocks, with coefficients $\mu_s$ and $\mu_k$ ...
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What is the optimal burn direction to lower periapsis of hyperbolic orbit?

I am an engineering student who is interested in orbital mechanics. I am doing some self study before taking some orbital mechanics courses next year. I was learning about various orbit types ...
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Is it correct that tires quickly get bald when used at high speed?

In my investigation, tires will quickly get bald if we ride a motorcycle at high speed. Is it correct? How to explain it in physics? Does the friction increase at high speed rotation? Update: The ...
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When is “Inertia” Negligible?

I have started to read Strogatz's Nonlinear Dynamics and Chaos and I have come across an interesting bit. He states certain damped oscillators may be modeled as having no inertia term, I.E. $$m ...
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Defy gravity torques with gyroscopes?

Context On the following drawing, a platform is hung from the ceiling not exactly from its centre of gravity. Because of this it can't sustain an arbitrary orientation for long; I want to increase ...