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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Reversibility in classical mechanics

I am watching Susskind's 'Theoretical Minimum' videos. At one point in his course on classical mechanics (2nd video if I remember correctly) he affirms that Netwon's second law of motion makes ...
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22 views

Transmissibility

An extract from a school maths mechanics textbook reads: To deal with cases in which the body is not rotating freely under gravity, we need to take into account also the work done by other ...
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1answer
72 views

Resemblance between Coriolis force and magnetic part of Lorentz force

If we interchange velocity with charge and omega that is rotation of a system with $B$, magnetic field, we get the same thing. Is there any deeper meaning to this same mathematical form?
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18 views

How to calculate the linear and angular dampening of a solid moving in a liquid? [on hold]

I am currently making a 2D physics simulation and I have to calculate the linear and angular dampening of a composite body (represented by a force vector field). I already calculate the linear and ...
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3answers
70 views

What is the difference between Newton's first & third law?

Newton first law states that object stays in fixed state, unless external force is applied. Newton third law states that: if there is action then there will be opposite & equal reaction. So if ...
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28 views

A block of mass M moving on a frictionelss horizontal surface collides with a spring of spring constant k and compresses it by length L [on hold]

A block of mass M moving on a frictionelss horizontal surface collides with a spring of spring constant k and compresses it by length L. What is the maximum momentum of the block after collision? ...
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3answers
69 views

About Kepler's Law

When Earth goes near the Sun, its velocity increases and when it goes far from the Sun its velocity decreases. Then why according to Kepler's law is the time period $T^2 \propto a^3$, where $a$ is the ...
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1answer
90 views

Parallel axis theorem

For this question we are working in 2-D space. Let's say that we have an arbitrary body. I know the inertia with respect to a perpendicular axis (to the body, that is) that passes through a point (A). ...
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1answer
25 views

Newton's Second law of motion: Elevator problem [on hold]

this is a question about newton's second law of motion that I am a bit stuck on. One end of the cable of an elevator is attached to the elevator car,and the other end of the cable is attached to a ...
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44 views

What arguments and examples did Newton give in support of Absolute time and space?

As everyone knows, Sir Newton advocated the Absolute Space & Time theory. But what examples and arguments did he confer to establish his theory? I read the wiki page where it was written that he ...
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1answer
41 views

3 pulley and 2 masses,relation between their accelerations [on hold]

I want to find acceleration of each mass in this system. lets take length of rope between three pulleys as $L$. then we can use this relations ...
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1answer
25 views

An unwinding cable problem [on hold]

Suppose a light cable is wrapped around a solid cylinder with mass $M$ and radius $R$. The cylinder rotates with no friction about a stationary horizontal axis. The free end of the cable is attached ...
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19 views

Which has more chance of floating: ring or sheet of same material? [on hold]

A ring and a sheet of same material, if kept carefully in water. Which will have a better chance to float and why? Also please explain the direction of tension force.
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2answers
109 views

What are absolute space & time? Why are they not absolute in reality?

As said by A.P. French in Newtonian point of view: Space is a sort of stationary three-dimensional matrix into which one can place objects or through which objects can move without producing any ...
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0answers
21 views

Working with problems including friction forces [on hold]

A body of mass $0.3 kg$ is taken up an inclined plane of length $10$ and height $5 m$ and then allowed to slide down to the bottom again.The coefficient of friction between the body and the plane is ...
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0answers
47 views

Force and Displacement: which come first? [on hold]

In nature, does force generate displacement, or displacement generate force? For instance, a spring oscillator, whenever you give a force, the displacement comes along and you will feel reaction ...
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4answers
82 views

Why are we still teaching Newtonian physics if it's “false”? [duplicate]

Why are we teaching an outdated theory when the math in general relativity isn't that hard? I really don't see a reason why we should teach a highly oversimplified theory in our schools. For me, it's ...
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2answers
97 views

Do objects really move in the direction of the force applied?

According to the second law of motion: Direction of the force is in the direction of change in momentum. Now, I came before a problem. Though an easy one, I was perplexed at a point. A ...
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1answer
57 views

The subtle differences between angular momentum and centrifugal force?

I am a mathematician wanting to understand the differences between the concepts of angular momentum and centrifugal force. The following two ideas are clear to me from a physical point of view, but ...
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1answer
41 views

Collisions in two dimensions: using relative velocity

I am following this tutorial which reviews some physics on collision resolution. I understand relative velocity, the mathematics is not a problem for me. However, despite my head scratching and ...
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0answers
42 views

Can someone please explain the forces acting on the rod? [on hold]

Can someone please explain the forces acting on the rod.
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1answer
41 views

Equation of Trajectory [on hold]

I was reading about Lorentz force law and motion of a charged particle under Electric field or magnetic field and I understood how they move in it. But as I was moving further I came across the ...
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0answers
10 views

Reference needed about history of classical mechanics [migrated]

Who discovered/ defined momentum and impulse? Please, I want suggestions about materials/ books on the development of Classical mechanics? Something like a history of experiments.
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2answers
63 views

Reasons for decaying orbit for satellites and spacecrafts

As per newton's law, unless a force is applies, moving objects will continue to move in a straight line. A satellite which speeds at around 17.5k mph would be travelling in a straight line considering ...
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2answers
69 views

How, exactly, does a reaction wheel work?

Reaction wheels, mounted on spacecrafts and satellites, are used for precision attitude control. It is not clear to me how they can do this, though. My best guess is that when a motor accelerates a ...
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1answer
126 views

A precise definition of macroscopic and microscopic objects

What are the formal definitions of "macroscopic object" and "microscopic object". How can one differentiate between them? I mean, is there any fixed condition by which we can distinguish between them? ...
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0answers
38 views

What is the form of the Hamiltonian for periodic boundary conditions? [on hold]

What would the potential term be for a system with periodic boundary conditions? I know the simple harmonic Hamiltonian, but what about a general system such as a wire? I'm trying to solve the ...
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26 views

Inclined pulley. Finding the $\frac{M_1}{M_2}$ [on hold]

Problem As you can see in the picture, $M_1$ and $M_2$ are attached by a massless rope over a pulley. the height difference of $M_1$ and $M_2$ is $h$. The masses start to move and after $τ$ seconds, ...
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1answer
22 views

Conditions of friction on constant acceleration [on hold]

If a body is moving with constant acceleration, then what would the frictional force be? Zero In forward direction, In reverse direction all of above
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0answers
25 views

Can a projectile moving at supersonic velocities leave a silhouette in whatever it hits?

I was recently reading this, and Floris's answer confirmed my knowledge that the information of an collision travels at the speed of sound. While I was thinking about that, my mind wandered and I ...
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1answer
37 views

Thrown object with air resistance [closed]

An object is thrown horizontally from height $h$ with initial velocity of $V_0$. Air resistance is given as $f = -\beta v$ I need to find the velocity and location at any given moment. I understand ...
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2answers
41 views

Understanding variable mass equation for mass ablation/ejection

The "Variable-mass system" entry in Wikipedia, under the "Mass ablation/ejection" title, shows: $$p_2 = (m+dm)(v+dv) + u(-dm)$$ The parameter $p_2$ is for the momentum at $t+dt$, meaning $p_2 = ...
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1answer
23 views

Conservation of generalized energies in Newtonian and Relativistic Systems

I was considering the following problem: In a closed system, it is assumed that mass, momentum and energy is conserved. If we label the total mass of the System $M(i)$ at a time i, the total Momentum ...
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1answer
23 views

Running Euler's disk in a superfluid

I was considering the toy Euler's Disk, a video can be found here: http://www.youtube.com/watch?v=mVl2CBG_h2s I was interested in understanding the behavior of the disk particularly in vacuum and in ...
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1answer
25 views

Making water spin a wheel [closed]

Let's say that I have a wheel with 8 symmetric arranged rectangular plates of area $A$ and the water, with density $\rho$, in the river it moves with $v\: \mathrm{m/s}$. How do I calculate the ...
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1answer
20 views

Do two engines with the same specific impulse always perform the same amount of work?

As the title say, do engines with different thrusts with the same $I_{sp}$ and the same amount of fuel perform the same amount of work?
2
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1answer
60 views

The work-energy theorem

Well here's the question. From some previous excercises we know that from \begin{align} A&=\int F\;ds,\\ &=\int ma\;ds, &&(F=ma)\\ &=\int m \frac{dv}{dt}\;ds, ...
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35 views

Rotational KE in double pendulum

Why the Rotational Kinetic Energy term for the point mass of Kinetic Energy for double pendulum is not included in Lagrangian equation? \begin{align} ...
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1answer
40 views

Action and Reaction - Time lag

Is there a time lag between action and reaction ? If there isn't such a time lag, the reaction force must cancel the applying force although they act on different bodies. My second question is that, ...
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2answers
142 views

How to find the center of mass of several objects in a 2d plane?

We have the following scenario in a 2d plane: a big rectangle with a lot of smaller similar uniform rectangles in it, all of them weight differently. Where is the center of mass of this object ...
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3answers
47 views

Do components of force have direction when doing work?

When we get angle > 0, the x-component of force is along the direction of displacement and so their product is called Work. So the x-component of force is said to have direction of the respective ...
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83 views

When we catch a falling object, where does its kinetic energy go?

Some of it is transformed into heat and noise, but where does the rest go? Further details: The object does not bounce off (e.g. a sack of rice marble ball). The hand remains completely static ...
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1answer
74 views

Ball flying towards me - Newton's third law is violated?

I was trying to answer the question of the flying ball here on the basis of Newtons third law and Momentum conservation. Here is what I have tried. Lets take $m_1$ (the ball) hits $m_2$ (the man). ...
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5answers
101 views

Does lunar module need the same amount of fuel for landing and take off?

Let's assume there is no atmosphere and let's assume there is no change in weight due to fuel consumption, will reactive rocket need the same amount of fuel for landing on a planet as for take off? ...
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2answers
57 views

How to actually account for air resistance?

What's interested me in my studies thus far is that in a lot of beginner undergrad mathematics and physics courses we're often told to calculate trajectories, velocities, etc. by "ignoring air ...
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32 views

Momentum in the frame of reference of the center of mass [closed]

I'm a high school student who just learned this topic in class today. I don't understand why the sum of momentum is zero in the frame of center of mass. Also, how can I solve this problem: Three ...
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0answers
21 views

Calculations to Determine Force Required for Gyroscopic Stabalization

I am currently undertaking a project involving gyroscopes, the aim of which is to stabilize a large object. I have read that gyroscopes work because of conservation of angular momentum, and if you ...
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2answers
88 views

Force of a Train

Imagine that there are two trains and the first train is twice as long as the second train. They have the same mass per unit length and they are traveling at exactly the same speed. If the first ...
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1answer
82 views

Questioning Einstein's view on gravity [duplicate]

Oke, so my mind is blown by Einsteins view on gravity, at least as far as I understand the basics and principles he based his views on. One of the first things that struck me was that most of his ...
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1answer
28 views

How do you find the tension in the real world? (Given a rope in a pulley system)

I'm well aware of the formula to calculate tension, however, given a real world situation where you have a closed pulley system. How do you measure the force (i.e., tension) required to pull on the ...