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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Work done in bringing down a body

A block of mass $30$ kg is being brought down by a chain. If the block acquires a speed of 40.0 cm/s in dropping down $2.00$ m, find the work done by the chain during the process. I have calculated ...
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1answer
24 views

What is exact difference between gravitational force and magnetic force?

I've read that gravitational force is due to mass only and magnetic field is due to moving charged particles. But my question is: what are other difference between them? Can we set up a small ...
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1answer
111 views

Rolling Friction Problem

The handbrake of a vehicle of mass $1.5\ \mathrm{tonnes}$ completely fails while it is parked on a $30^\circ$ slope. It rolls $20\ \mathrm{m}$ down the slope before colliding with, and locking on to, ...
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Keplerian orbits and radial velocities: problem with true anomalies

I am writing a pure Python code to calculate radial velocities of stars with massive objects orbiting them. I am following the formalism from Murray & Correia (2011) (hereafter MC11). In a given ...
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1answer
54 views

What does $P = Fv$ mean?

The engine of a car is developing a power of 90kW when it is moving on a horizontal road at a constant speed of 100 km h−1. Estimate the total horizontal force opposing the motion of the car. I ...
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25 views

Newton's third law confusion [duplicate]

If A exerts a force of 200N on B, then by newton's third law, 200N would be exerted on it. Similarly, if B exerts 100N on A, by newton's third law, 100N would be exerted on it. Therefore the net ...
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0answers
36 views

Gimbal Lock: why is it a problem?

I was watching this video http://www.youtube.com/watch?v=rrUCBOlJdt4 about the gimbal lock problem. I understood that during rotations it could happen that one DOF disappear. Looking at the middle ...
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4answers
4k views

When an object moves downward, is its height negative?

The question is: A ball is thrown directly downward with an initial speed of 8.00m/s from a height of 30.0m. After what time interval does it strike the ground. So I went through the problem ...
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3answers
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If we threw a baseball from the ISS, could we deorbit the ball?

Clearly this is a hypothetical question. Say we bring a star baseball player into NASA, prep them appropriately for a mission in space, and fly them up to the International Space Station. They go on ...
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0answers
21 views

I need results or to conduct a simple experiment for a dynamics problem involving the range of a projectile launched from a pendulum

I have created a model to show how the maximum range of a projectile varies with respect to the velocity and angle of when the object is launched from a swing. I now need to compare these results ...
-3
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1answer
29 views

In this energy conservation problem, why are the answers different with different units? [on hold]

Really basic question, but basically I'm given a change in height in centimeters (that's how I measured it). From that, I'm supposed to find the initial kinetic energy. $KE_i = PE_f$ After doing ...
5
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1answer
37 views

Understanding potential energy

I am self-studying the classical mechanics using the book by Taylor, and I have a question about the potential energy. The book (pg 111) says: If all forces on an object are conservative, we can ...
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1answer
46 views

Water Moving Through Coffee Grinds

Like many of my peers, I rely on coffee as if it were prescribed to me. It might even be classified as an addiction if it weren't for the cultural norms surrounding a cup of coffee or tea in the ...
0
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2answers
109 views

Angular momentum about a moving axis

How can we define angular momentum of a system about an axis that moves parallel to itself? For example Axis passing through CM that is perpendicular to plane of body. When we talk about ...
2
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2answers
939 views

What are the general solutions to a hard sphere collision?

Surely someone has found the solutions to the hard sphere collisions (in $n$ dimensions) of two bodies of mass $m_1$ and $m_2$, respectively--that is the resultant velocities (or momenta) of the two ...
0
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1answer
41 views

Calculate the speed of Halley's comet at his perihelion [on hold]

Knowing that Halley's comet orbita the sun every 75,3 years, that the semi-major axes is 17.83 AU, the semi-major axes is 4.53 AU and at his perihelion he is 0.586 AU away from the sun. With these ...
53
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8answers
51k views

With Newton's third law, why are things capable of moving?

I've got a rather humiliating question considering newton's third law "If an object A exterts a force on object B, then object B exerts an equal but opposite force on object A" -> $F_1=-F_2$ ...
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1answer
473 views

Block Sliding Down a Plane (Perpendicular Velocity)

I'm having trouble understand the concepts for this problem. Here's the problem: A block is placed on a plane inclined at angle $\theta$. The coefficient of friction between the block and the ...
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2answers
231 views

Changing momentum of moving trolley

Consider a trolley of mass $m$ moving at a velocity $v$ along a smooth horizontal plane. It is full of water, and water is leaking at a constant rate out of the bottom of the trolley, i.e ...
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0answers
16 views

Testing diamagnetism of water while somehow breaking the 3rd law of physics [on hold]

I am having trouble explaining how the following experiment actually works, but it does.? Place a neodymium magnet on a piece of Styrofoam and a test tube of water next to it on the same piece of ...
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2answers
450 views

Horizontal and vertical acceleration of a ball on a slope?

I understand that you resolve the components of the balls weight parallel and perpendicular to the slope in order to calculate the force due to gravity that actually acts down the slope. The ...
5
votes
4answers
404 views

What will be final velocity of three charges $q$, $q$, $2q$? [closed]

What will be final velocity of three charges q, q and 2q kept along an equilateral triangle of side r at infinite distance. All three masses are equal. I tried to conserve Total Energy ...
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5answers
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1
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1answer
72 views

Where is the mistake in the following rationament [duplicate]

Well... kind of hard to translate in English so bare with me :). Let's consider a wheel that spins in the void. Each point of the wheel has the speed $v = ω r$. That means that for any $ω$, there is ...
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1answer
62 views

Why does holding an object cost energy while no work is being done?

I was reading the discussion here: Why does holding something up cost energy while no work is being done? I feel as though the question is being avoided. Suppose instead of holding an object by hand ...
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2answers
331 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, ...
0
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1answer
54 views

Find the acceleration of the bead [on hold]

Two identical, uniform large rings, each of mass $\text{m}$ are connected through a bead of same mass, which can move freely. When bead is released, it starts sliding down. The large rings roll ...
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2answers
654 views

In wave motion of a string both kinetic energy and potential energy are minimum at $y=y_\text{max}$ then why does the string comes down again?

In wave motion of a string both kinetic energy and potential energy are minimum at $y=y_\text{max}$ then why does the string comes down again? As everything in tries to attain lowest energy possible ...
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2answers
55 views

Pseudo force/negative acceleration

The goal is to find $\boldsymbol {a_0}$ I already have the solution, however, I have a few questions. In the solution they have taken $\boldsymbol {m_2}$'s acceleration relative to the ground to ...
3
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1answer
16 views

How would I find the velocity of an object after it doesn't fully enter the gravitational pull of a planet and is kind sling shot out of its gravity?

Obviously that question doesn't have a lot of jargon having to do with math and physics. I am not a physicist, I'm not a mathematician, I'm trying to make a game and simulate some physics found in ...
1
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1answer
33 views

Conflicting answers gained from different equations

First time posting I hope this is the place. if someone could help me sort out formatting for the equations that would be nice "As a result of being hit from behind by a toy truck, a 50g toy car ...
0
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1answer
20 views

Effect of wall friction on stagnation pressure and temperature

We have incompressible air flowing through a cylindrical pipe, from section A to section B. The process is considered to be stationary. My theory book says that, because of the frictional losses on ...
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2answers
31 views

Centripetal force and friction

Here is the question I need help on: A hemispherical pile of snow with a height of 20 m is piled up. An extreme skier starts at the top of this snowball, and she skies down finding that ...
1
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1answer
119 views

Disk and Ball on a smooth surface [closed]

A uniform disk of mass $\text{2m}$ and radius $\text{R}$ is placed freely on a smooth surface as shown in the figure. A particle of mass $\text{m}$ is connected to the circumference of the disc with a ...
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2answers
43 views

Dynamics of two pulleys [on hold]

I have been trying to do this exercise for 2 days but I'm sure that I'm negleting something... Here is the sketch of the situation: $$m_A= 4M \\ m_B= M \\ m_C=2M$$ All the strings cannot ...
1
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1answer
103 views

Ball Rotating in Place Under Waterfall

https://www.youtube.com/watch?v=Khf6koh3IO8 Can anyone help me explain this? It seems like the ball should shoot out from underneath. I have two main theories. 1) Bernoulli's Principle says that the ...
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3answers
28 views

Phases and sinusoidal waves

When we're talking about a wave, just a singular sinusoidal wave, what exactly is a 'phase'? I came across a question that gave values of frequency ($550$Hz), and speed ($330$m/s). The question then ...
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votes
2answers
41 views

Condition for a particle to move on a sphere

Is it possible for a particle of mass $m$ to complete a circular path on a sphere if it starts from the topmost point and no external force acts on it except gravity and frictional force between ...
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0
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2answers
62 views

Is time a coordinate or a parameter in Newtonian mechanics?

In classical (Newtonian) mechanics we only ever seem to consider 3-dimensional space, with physical quantities being represented by 3-vectors. My understanding for this is because in classical ...
-1
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0answers
22 views

Coupled spring mass-system [on hold]

Below is an old exam question I am trying to solve (it's not homework or an assignment, just an interest of mine). I have a few gaps in my attempted solution that I would like help with. Specifically: ...
-1
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1answer
29 views
0
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0answers
48 views

Blue bird physics- Angry Bird

This is a question from my assignment which is Angry Bird related. Here it is: Before designing new types of birds for the Grumpy Birds game, you are asked to first verify the design of one of ...
0
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1answer
42 views

Can drag force and lift force be in the same direction in the following case?

In the attached picture, can I say that there is a lift force in the Y-direction, and a drag force too in the same Y-direction? $F_L$ proportional to $V_fx^2$ ? $F_D$ proportional to $V_py^2$ ? Is ...
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0answers
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0
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0answers
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Will the force acting be doubled? [duplicate]

If me and a man are holding a string, and I apply a force of 100N, the tension in the string would be 100N, and it would exert a 100N force on the man and an equal and opposite force of 100N on me. ...
0
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0answers
24 views

Quick question on rotational motion [on hold]

This is a quick one. (AP Physics B 1977): A box of mass M, held in place by friction, rides on the flatbed of a truck which is traveling with constant speed $v$. The truck is in on unbanked circular ...
0
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0answers
28 views

Grade 12 Projectile Motion Problem [on hold]

A cannon is placed 100 m from the edge of a cliff that drops 150 m to a canyon floor. Exactly 4 seconds after being fired the cannonball misses the edge of the cliff on its trajectory to the canyon ...
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2answers
161 views

Do all forms of energy fall under kinetic and potential energy?

I know that energy is recognized through motion. Even in the mass-energy equivalence a velocity is present even though it is a rest-energy (Not really sure if this would count as a potential energy ...