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.

learn more… | top users | synonyms (3)

1
vote
1answer
73 views

Can 4 collinear planets exist?

Imagine 4 planets, A has moon a and B has moon b. A and B are binary planets. Is it possible that a and b and A + B all have same the period, so that the 4 planets are collinear?
1
vote
1answer
97 views

Why friction force peak just before the object moving?

This diagram shows the amplitude of friction force of a typical contact-surface object. The friction force increases as we apply an internal force until it reach a maximum value just right before ...
1
vote
3answers
279 views

How can Kinetic energy formula and the Work formula be derived without assuming the other to be true?

After searching how to derive the formula for Kinetic energy, I found that most derivations required the use of the "work" formula. After searching how to derive the work formula for a bit, I found ...
1
vote
2answers
66 views

Guidelines for $n$-body problem inital conditions

I'm trying to solve a 5-body problem (for the sake of the argument it can be any given $n$) numerically, yet every initial condition I choose seems to eventually drive the bodies apart to infinity or ...
1
vote
2answers
39 views

Collision of Inelastic ball above the ground

An inelastic ball of mass $m$ is dropped from a height $h$ above the ground and at the same time a second ball of mass $m_1$ projected vertically upwards to meet the former. Show that in order that ...
1
vote
2answers
133 views

Paradox of potential energy of gas molecule

We know that when water is heated at its boiling point, it will become vapors. Then because there is no change in temperature, the heat supplied will be transferred to the potential energy of the ...
1
vote
2answers
117 views

Appearance of the Jerk Term in Dynamics of Mass-Spring-Damper System

I am coming from the computer science territory and have not a long trace in mechanics. My background in derivation of the system dynamics could be summarized with utilization of the ...
1
vote
2answers
52 views

Some confusion pertaining to direction of static friction on stationary object

Consider a stationary object of mass $m$ on a horizontal table. Since the object does not move relative to table, $f_s=0$. So it seems that we first consider $mg$ and normal reaction force,$N$ ...
1
vote
3answers
191 views

Why can't we find a true inertial frame?

From one book, I read that if we release a ball horizontally on earth, its velocity does change in very accurate observations. If we track its motion, we get full information of its motion (incl. ...
1
vote
1answer
103 views

Newtonian motion of a particle confined to a smooth surface

Recently, I've been considering a model wherein a lone particle with constant mass m is confined to a surface $F$: $\mathbb{R}^m \to \mathbb{R}^n$ , where $m < n$. I declare this surface to be ...
1
vote
2answers
110 views

Tension in a massless string as it bends around a concave shape

I understand that tension in a massless string must be the same throughout when the string is straight, to prevent any section of it from accelerating at an infinite rate. However, I fail to see how ...
1
vote
3answers
114 views

Is work-kinetic energy theorem useless?

This is how my book explains it: $W_{net} = \delta K$ Since the net work is tied to changes in kinetic energy and changes in speed, a mass must accelerate in order for net work to be nonzero. ...
1
vote
2answers
76 views

Saturn V horizontally attached to Earth

If the Saturn V rocket were attached to the ground facing in the opposite direction of the Earth's spin, would it in anyway slow the Earth's spin on its axis? How significant of an impact would it ...
1
vote
3answers
126 views

How does The work done in going around any path in a gravitational field is zero implies conservation of energy?

In The Feynman Lectures, Feynman states: The work done in going around any path in a gravitational field is zero. This is a very remarkable result. It tells us something we did not previously ...
1
vote
3answers
596 views

Tension in a rope

In an ideal case, we assume strings and ropes to be massless and having same tension throughout. However, I was doing some questions which involved a rope with mass. The question was that if a ...
1
vote
3answers
59 views

Problem with black holes?

I understand that black holes are formed when supermassive stars (>10 times the size of our Sun) die. When they die, their cores continue to shrink. I have read that eventually the core reaches a ...
1
vote
3answers
932 views

Calculate acceleration from power [closed]

I am currently programming a simple computer space ship simulation. This is just for fun to train my programming, 3D graphics and a little bit of physics skills. What I want is the user to pick a ...
1
vote
1answer
32 views

Effects of vertical circular motion to the body weight

Our body weight will experience the differences when moving at constant speed in a vertical circular motion such as roller coaster. Why do we feel heavier when at the bottom of the loop and lighter ...
1
vote
1answer
176 views

How much does air resistance affect the angular velocity of a golf ball?

I'm modeling the flight trajectory of a golf ball, and using angular velocity to calculate the Magnus force. Currently, I'm assuming angular velocity to be fixed throughout the ball's flight. How ...
1
vote
5answers
208 views

Why does solving $\mu mg = m \frac{v^2}{r}$ give the *max* possible velocity?

So here is the standard problem setup of a car turning on an unbanked road: A 1000 kg car is going around a curve with radius 30 meters. If the coefficient of friction between the car's tires ...
1
vote
1answer
60 views

Warship cannons influence on speed/direction [closed]

I've been looking at great warships like the Iowa or equivalent ww2 warships, and I raised question. This kind of war is pretty much only about strategic placements, accuracy and fire power. Hence ...
1
vote
3answers
340 views

Scale on an elevator

When you are accelerating upwards in an elevator, you feel an increase in apparent weight. A scale measures the total amount of force pushing down on it, and if you were to step on a scale in an ...
1
vote
2answers
581 views

Will increased weight slow a pendulum?

When a pendulum is swinging, if you could instantly add significant weight to the bob without altering it in any other way, will that weight increase drag and cause the pendulum to move to equilibrium ...
1
vote
2answers
196 views

Linear momentum experiment

trying to design an experiment for linear momentum. Could someone tell me whether this would work. Get a wooden toy car and attach it to some string which is hung over a pulley on the end of the ...
1
vote
1answer
56 views

Undamped Resonance of a Classical Harmonic Oscillator

Consider an undamped harmonic oscillator. It may be driven at it's natural frequency, $\omega_0^2 = \frac{k}{m}$. According to Feynman, and other sources, were this to happen, the amplitude of the ...
1
vote
2answers
79 views

Deriving the velocity for circular orbital motion

I'm trying to derive the (circular) orbital velocity for a given height from the center of mass of a body, like Earth. First I used the equation of the circle $x^2 + y^2 = r^2$ to get $y = \pm ...
1
vote
2answers
57 views

Proof that oscillations in 1d potential well occur between certain points

In >>this<< situation, a particle with energy $E$ will oscillate between the positions $x_1$ and $x_2$ indicated on the diagram. This simple fact is taught in many introductory courses however I ...
1
vote
1answer
197 views

After a glancing collision, why do air hockey pucks spins around in circle?

For a lab testing the conservation of momentum, I had to hit an air hockey puck so that it would hit another stationary puck in a glancing collision. After the pucks collided, they travel their ...
1
vote
1answer
62 views

Where would be the source of thrust for a rocket thruster in space?

I am making a game that involves spaceships and I was building an engine block. That engine block spawns a "thruster fire" under it that represents the...thruster fire. My question revolves around ...
1
vote
1answer
84 views

Can you determine acceleration from positions and velocities only?

I just began reading the Landau and Lifshitz book on classical mechanics. It states on the first page of Chapter 1 that: Mathematically, this means that, if all the coordinates $q$ and velocities ...
1
vote
1answer
81 views

Kettlebell squats center of mass

I should, first of all, state that I have very limited knowledge of physics but as a fitness enthusiast the following question has puzzled me for a while. When I do squats on the gym holding a ...
1
vote
2answers
70 views

How would a plane hitting a ball move (opposite of Pong)?

When a moving ball hits a stationary plane at an angle of incidence to the normal, it bounces away at the same angle (the angle of reflection), which is commonly understood. My question is 1) What ...
1
vote
5answers
166 views

Which one acts first: friction or tension?

I have a block kept on a rough surface with a string attaching it to the wall. I pull the block opposite to the string with a certain force $F \leq \mu mg$ where $\mu$ is the coefficient of friction ...
1
vote
5answers
2k views

How can static friction do work?

By definition, the work done by a force is $W = F\cdot d$, so how can static friction do work? Can this force move the body a distance of $75~\text{m}$?
1
vote
2answers
109 views

Confusing, can a motor on a moving disc stop the disc?

I've been troubled trying to solve this problem. If a motor is fixed on a moving rotating disc and the motor's rotor has another disc attached to it. What would happen if we attached the motor's ...
1
vote
1answer
105 views

Angular velocity and instantaneous rotation axis

Let's suppose that we have a cylinder of moment of inertia $I$ rolling on the floor without sliding, moving with linear velocity $v$ and rotating around an axis passing through the center of mass with ...
1
vote
2answers
199 views

Why is momentum conserved in inelastic collisions? How is it related to momentum-impulse theory?

First of all I want to mention, that I've found many questions around this site and in other websites dealing with my question; however, I don't think they answer my question fully. So I am here to ...
1
vote
2answers
117 views

How this formula for work follows from the definition?

If a particle moves along a path $\gamma : I\subset \mathbb{R}\to \mathbb{R}^3$ then the work done by a force $\mathbf{F}$ is defined by $$W = \int_{\gamma} \mathbf{F} = ...
1
vote
1answer
366 views

If I bend a rod, will its moment of inertia change?

In the first picture, there is a homogeneous metal rod of length $2L$ and mass $M$. If it rotates around a normal axis passing by $O$ (which is the center of gravity), then its moment of inertia is: ...
1
vote
1answer
202 views

Free fall of mass-spring-mass system

I am a little bit confused about the implication from my computation. Must have done something wrong in the computation. Assume we hold the top end of the mass-spring-mass system in the air, and the ...
1
vote
1answer
97 views

Equations of motion for a rocket

I'm trying to figure out how Tsiolkovsky rocket equation is derived. I've tried following along in the Wikipedia page and from my book, but I'm not getting it. First, are they assuming the ...
1
vote
2answers
129 views

Is my answer possible? (Newtonian Third Law Pairs and Forces, Multiple Choice Word Problem)

So I recently took a test and the teacher graded my answer correct, yet my friends saw that the other answer was correct and they protest that it should be the right answer: The question goes: ...
1
vote
1answer
821 views

How do I find the angle given the mass, the acceleration and the force acted on a body?

My Issue I have the mass, the horizontal acceleration and a force that acts on a body. The force forms an angle $\alpha$ of unknown degrees with the x-axis. I would like to know how I can find the ...
1
vote
2answers
251 views

Does the conservation of linear momentum for a ball hitting a wall and changing direction?

The conservation of linear momentum essentially says: $$\sum m \vec{v_1}=\sum m \vec{v_2}$$ But if I take the absolute value of both sides, and drop summation, is it also equivalent to say that: ...
1
vote
2answers
112 views

Problem with an exercise: position and velocity of a thrown sphere with non uniform acceleration

You stand at the earth's surface, have an object, for example a sphere, of mass $ m_1 $ and throw it with a velocity $ v_1 $ into the atmosphere, perpendicular to the surface. Let $g$ at the surface ...
1
vote
1answer
657 views

Elastic Collisions and Relative Velocities

In a 1D elastic collision, it is well-known that the relative velocities of the two objects (before and after the collision) are reversed. What is the extension of this result to 2D or higher? Is ...
1
vote
3answers
126 views

A problem related to Work done by falling bodies : Expert's attention much needed! [closed]

I'm having a lot of trouble with this question, that I've found in my textbook. I've solved it in my own way and it's very simple! But the solution in the book is totally different. It doesn't make ...
1
vote
2answers
80 views

What is the use of orthogonal curvilinear co-ordinate system?

Orthogonal curvilinear coordinate system is made of intersecting sets of confocal ellipses & hyperbolas. But, I have found no book that would describe this how to use this coordinate system ...
1
vote
1answer
110 views

Stagnation Point around Sharp Corner

I am trying to design a water-channel that travels through a metal block shaped like a square to cool it down (so it is a 2D problem). One consideration is the wetted surface area, which allows more ...
1
vote
2answers
151 views

Polar moment of inertia of a cylinder

So I know the polar moment of inertia of a solid cylinder is: $$ I= \frac{1}{2} mr^2 $$ My question arises with the polar moment of inertia uses for solid cylinders in my mechanics of materials book, ...