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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Motion of an object in rotating frame

Yesterday I was looking at an old sloan video that describes motion in inertial and non-inertial frame. An experiment was actually like this. Two persons are sitting on the opposite side of a table ...
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24 views

Atmospheric pressure

Whats the significanc of Atmospheric pressure being refereed as 100kPa ? Does that really mean 10000 kg/m2 acting upon us ? If we are measuring only collision force on the surface and not the weight ...
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2answers
417 views

How do I describe the order of events in spacetime?

In Newtonian mechanics, we have 3-space and time. Time allows us to order events. For example, I hold a ball in the air at time $t_0$. Then I drop it at some later time $t_1 > t_0$. Finally it hits ...
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3answers
100 views

How big bang could produce later collisions

The Milky Way and the Andromeda galaxies are supposed to "collide" in 4 billion years (collide in the sense of overlapping space, but nothing is really supposed to contact anything else). Assuming: ...
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1answer
74 views

What is the reason behind the equation $p = mv$? [duplicate]

Now this is a very basic question, might look stupid too, but I am not able to understand it. I tried to imagine what momentum really is, and it is the impact of an object. I understood how momentum ...
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3answers
58 views

Why is there potential Energy due to lifting an object or moving when it's attached to a spring while the net work is zero?

Consider that you lift an object a height h vertically, if the body happens to move with uniform velocity this means that net force acting on it is zero. The same is true for a body attached to a ...
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2answers
44 views

Work done by a spring

I've done enough research before asking this question. The work done by a spring is defined as $$W_\mathrm{spring}=\left|\frac{1}{2}kx^2\right|$$ Where $ k$ is the spring constant and $x$ is the ...
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56 views

How is Temperature and Pressure related to when a tire rolls on the ground?

Actual observation: Here in Canada it is known that even when 'dry' snow is on the ground, and when a car drives over it that small amount of dry snow instantly becomes ice (NOT GOOD). Anyways as an ...
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24 views

The precession component in the direction of spinning

Is the precession increasing the rotation around the axis of spinning? w = (nutation) i + (precession component) j + (another precession component + spinning) k or to rephrase, is the precession ...
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0answers
17 views

Model of a body - center of mass [closed]

I have to model a so called "seven-body-mechanism". Looking in detail at K5 Is it possible to model the body "K5" as a straight body with the center of mass at (ta/tb)? Thanks for your help!
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1answer
89 views

Why isn't $E=mv^2$ a general formula for energy?

This is the usual derivation of the formula for kinetic energy: $$\begin{align} \mathrm{d}E &= Fv\,\mathrm{d}t \\ \mathrm{d}p &= m\frac{\mathrm{d}v}{\mathrm{d}t}\mathrm{d}t \\ \mathrm{d}E ...
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1answer
44 views

Is the integral of $dK$ equal the work done?

$$\frac{dK}{dt} = \frac{d}{dt} (1/2 mv^2) = mv \frac{dv}{dt} = F\frac{dx}{dt}$$ $$\implies dK = F. dr$$ Also, work is defined as $W = \int F. dr$. So does this imply integral $dK = W$?
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58 views

An intuitive explanation of the so called Galileoʼs theorem

The statement of the theorem is as follows (see Francisquini et al, Physics Education, Volume 48, Number 6, November 2013): Prove that the time taken for a particle to slide from the highest point, ...
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41 views

Why are Newton's laws valid only for rigid bodies?

As far as I know, Newton originally wrote the first and second laws for a particle and under the condition that a collection of particles is rigid, we can write newton's second law for a body as ...
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1answer
34 views

Decomposition of Spring

Can a spring respectively its stiffness in a 2D-system be decomposed into its x- and y- components (stiffnesses)? Assuming a spring located in an 2D coordinate system with positions p(x,y), length l ...
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1answer
45 views

Why do we only feel the centrifugal force?

After spending some time researching about the centrifugal force, I now understand that it is needed in a non-inertial reference frame for Newton's Laws to hold true. However, I don't understand why ...
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2answers
53 views

Why doesn't a particle in uniform circular motion fall into the centre? [duplicate]

If a object is in uniform circular motion, I know there is a acceleration directed radially inward. If that's the case, shouldn't there be a velocity radially inwards at some time. If that's true. Why ...
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0answers
29 views

The relation between work and time

Work equals the force acting on an object times the distance that object moves. But I am a bit confused about the definition of the distance. is it the distance the object moves under the effect of ...
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1answer
46 views

Effective mass of two objects

I read that if we want to perform conservation of energy taking one object as frame of reference, we need to assume that the other object has the effective mass and velocity. And effective mass is ...
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1answer
30 views

can a single force rotate an object. not a torque

Can a single force (not a torque) rotate an object? How can the bar below fall given the force $\mathbf F$?
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3answers
387 views

Do raindrops spin as they fall?

I'm wondering if a drop of water starts to spin as it falls. Also, does this spin increase until the drop slings itself apart or does it have a terminal spin velocity?
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2answers
95 views

Why are gravity and spring-force conservative forces?

I know that the amount of work does not depend on the followed path but on the position when speaking about conservative forces. But could someone please prove/explain why exactly those two are ...
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4answers
133 views

Is my understanding of Newton's third law correct. And why is this law taught the way it usually is? [closed]

For years, Newton's third law has always bugged me. Sure, on some level I could believe it. After all, it must be true else I wouldn't be able to jump off the ground. But it always seemed extremely ...
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1answer
27 views

How far will the key slide? [closed]

A person tosses his car keys on a shelf with an initial velocity of $2\:\mathrm{m/s}$. How far will the keys slide if the coefficient of kinetic friction between the surfaces is $0.3$? How would you ...
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0answers
21 views

What is the form of energy that is forming while i am holding a suitcase an not moving at all [duplicate]

If I am lifting a heavy suitcase and I am not moving at all. Abviously I am not doing work because I am not moving or rising the suitcase up and down. But abviously I am losing chemical energy since ...
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3answers
57 views

When walking, why the foot which get the reaction doesn't accelerate?

To walk we apply a force and the earth gives us a reaction. But the foot which get the force doesn't accelerate.
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2answers
91 views

How apply $\mathbf{F} = m\mathbf{a}$ to a whole pulley system?

When we are dealing with systems of bodies we apply $\mathbf{F}= m\mathbf{a}$ to the whole system. How do I apply $\mathbf{F}= m\mathbf{a}$ to the whole system in the following example.? ($m_1 \lt ...
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1answer
20 views

Restoring force in circular rod

Can somebody explain how to calculate the restoring force in a uniform circular rod with known Young's modulus and diameter. I would need the restoring force in a specified distance from the origin ...
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0answers
26 views

Friction between $n$ surfaces? [closed]

Since two weeks ago, I have been working on a project where $n$ things are overlap together (with different coefficients of friction) for getting the force that's need for pulling them apart. Could ...
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0answers
24 views

How does a bikerider turn by leaning on one side? [duplicate]

I am trying to understand the following image: Could someone please help me understnding it. What I understood so far: Your angular velocity mutyplied by the impulse gives you the impulsemoment. By ...
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1answer
38 views

Why is it easier to steer a car at speed?

If I am trying to park my car, a power steering system really helps. However, you can't really feel the difference once you get up to speed. Power steering barely offers any assistance at motorway ...
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2answers
54 views

How can we make the equation of second law of motion by this info.? [closed]

First of all, I am really sorry if this question is bad. I was thinking about the second law of motion, the famous $F=ma$. I was trying to get the idea behind this equation, I got some ideas but I am ...
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2answers
24 views

Confusion regarding resolution of forces

I'm looking at a basic free body diagram of a car travelling on a banked(inclined) road with inclination theta. It's mass is 'm'. Here the diagram shows weight (mg), Normal reaction(N), and ...
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28 views

The force of a spring

I am new in continuum mechanics and I want to prove the formula which gives the force given by a spring : $$F_{max}= \frac{Ed^4(L-nd)}{16(1+\nu)(D-d)^3 n}$$ where : $E$ – Young's modulus $d$ – ...
3
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1answer
58 views

Velocity of particle constant under null initial magnetic force

I have got a doubt on the exact application of Newton's first, and third, law. Let us for example suppose that a particle, electrically charged with charge $q$, is moving at the instant $t=0$ with ...
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1answer
37 views

Can a uniform circular motion be considered as simple harmonic motion? [duplicate]

The acceleration in a circular motion is directed towards the centre and is directly proportional to the radius of circle if it has uniform angular velocity. Is circular motion with uniform angular ...
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2answers
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Horizontal net force question [closed]

A 1580kg car travels at 15m/s, what would the magnitude of the horizontal net force required to bring the car to a halt in 50m?
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1answer
57 views

Applying conservation of energy on a springs/projectile motion problem

My physics teacher proposed a hypothetical problem to our class as we are nearing the end of the Work-Energy Unit (that will in all likelihood show up on the test). I will probably have various ...
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1answer
107 views

Can Newton's 3rd Law be considered as a direct consequence of the coulomb's law of electric interactions? [closed]

Let me explain my thought. Lets consider Coulomb's definition of electric force between two charges as the fundamental law. Under this consideration, forces between charges already follow What ...
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2answers
69 views

If you lift something does the internal energy increase or remain unchanged?

So change in internal energy $\Delta U = q + w$; so in lifting an object you do work on it, thus increasing its internal energy. Is this correct? Sorry if this is a stupid question.
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140 views

Why didn't the glass break?

In the figure below, a needle has been placed in each end of a broomstick, the tips of the needles resting on the edges of filled wine glasses. The experimenter strikes the broomstick a swift and ...
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2answers
40 views

Equilibrium on a fixed wedge

While solving a question I came acrross this doubt.For a block in equilibrium on an inclined wedge, the summation of forces should be equal to zero.I am confused because I got two different results ...
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1answer
51 views

Angular Momentum and Kepler's Second Law

Let me preface by saying that I get the gist of the conservation of angular momentum, at least qualitatively. To better illustrate my question, I will consider the case of a planet orbiting a star. ...
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32 views

Spin is a tangent vector?

I'm trying to motivate the existence of various bundles related to non-relativistic quantum mechanics. The definition of spin structure with respect to the frame bundle of space implies that spin-1/2 ...
3
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1answer
55 views

Parallel axis theorem: adding mass

I'm going through a worked physics problem and have a question about the parallel axis theorem regarding only adding mass while not changing is axis of rotation. Here is the problem: A physics ...
1
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0answers
48 views

How can we solve 2D rigid body collision? [duplicate]

I know that usually collision with velocity collinear can be solved by simultaneous equations of both conservation of energy and linear momentum. But my question is when 2D velocity is encountered, we ...
3
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1answer
52 views

Conservation of linear momentum and velocity of a system (damper and spring in a series)

This example is from a book on dynamics. Let us consider the system above formed by two blocks (each of mass $m$) connected by a linear damper and spring in a series. They slide without friction on ...
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1answer
45 views

Spring Potential Energy [closed]

A spring whose spring constant is $k$, having an initial "free" length is $l$, is being pressed by $2$ hoops on a metal(the parabola) on his both sides. (see image below) I want to calculate the ...
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3answers
394 views

What does it mean to say work is path-independent when pushing an object in different directions?

If I apply a straight upward(perpendicular to ground) force against gravity of $5\ \mathrm{N}$ and lift an object "A" 10 meters, then the work done is: $$ W = F \times S = 5\ \mathrm{N} \times 10\ ...
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49 views

Does a planet's orbital angular momentum affect its rotational angular momentum?

For example: If the moon was closer to the earth, assuming the orbital momentum was conserved and not worrying about earth's rotation, would the moon's rotation rate be effected?