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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Obtain rate as a function of position for a force $F=-b\left( \frac{\partial x}{\partial t} \right)^{2}$

I have trouble getting the speed as a function of position for a force of the form: $$F=-b\left( \frac{\partial x}{\partial t} \right)^{2}$$ I had thought to use Newton's second law, so: ...
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173 views

Does our current notion of velocity/acceleration (based on calculus) require absolute time?

When people explain special relativity, they say that a velocity in one frame leads to time dilation in that frame relative to a stationary frame. When we say something like ...
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0answers
219 views

Numerical solution of two coupled second order differential equations of motion [closed]

Is there a numerical algorithm for solving a pair of coupled second order differential equations? This question arises from a homework problem that I have that involves two dimensional projectile ...
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1answer
60 views

Propulsion force [closed]

My physics instructor gave us a general problem A box is sitting motionless on a rough, horizontal patch of ground. You give it a good kick, so that it slides to the right with an initial speed of ...
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1answer
107 views

Can walking provide electrical energy?

This is more of a theoretical question, but is it possible to convert the energy you use to walk into electrical energy to say, power a light bulb?
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70 views

Power and speed [closed]

I'm asked to calculate how much POWER a 1210kg car needs to drive with a 85 km/s speed up a 655 meter long slope of 4.5°. I can find how much energy and work is required to do this, but isn't ...
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2answers
42 views

Final position of an object after aplying several horizontal forces [closed]

I'm given an object with a starting position. Several horizontal forces are applied to this object one after the other for different amounts of time. How can I determine the final position $x$?
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0answers
60 views

Bullet energy loss in solid materials [closed]

Does someone know simple model of energy loss in solid materials for a solid bullet? For example: I want to estimate momentum transferred to a thin plastic plate given by a small bullet. No matter ...
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1answer
43 views

Why can we use the energy of a pendulum to calculate its frequency?

The question might sound rather vague; to calculate the frequency using the energy we simply use that the total energy is constant, set the derivative to zero and solve the equation of motion that ...
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1answer
92 views

How to find the center of mass? [closed]

A massless rod of length $L$ attached to mass $m$ and with axle to cart of mass $M$. The cart has a shape of equilateral triangle (edge $L$). the cart is at rest and its center of mass is above $x=0$ ...
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2answers
156 views

How to simulate a full-suspension bike? [closed]

As a fun project, I would like to roughly simulate the suspension operation of a full-suspension mountain bike. This is not another one of those "How does a bicycle stay upright?" questions. Follow ...
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76 views

Classical disintegration of particles, Landau-Lifshitz series on Physics

i read Landau's book recently. In this book p.43 Landau says from (16.1) (16.2) can be write down $T_10$= $p_0^2$/2$m_1$=($M-m_1$)($E_i-E_1i-E_i'$)/$M$ For me, it is hard to understand the factor ...
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86 views

Moment of inertia of a system in different cases

A rod of mass $m$ and length $l$ is pivoted at one end to ceiling and free to rotate in the vertical plane. A disc of radius $R$, which is less than $l$, can be fixed at its other end in 2 ways : ...
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2answers
181 views

Two suns, one moon, and one planet?

I have a question about how would seasons and the moon cycle be affected in a system where one planet orbits Sun #1, and Sun #1 orbits a second sun. Online I found this description: "Type II: ...
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2answers
99 views

Can a car skid while moving in a circle?

How can a car skid if it is moving around a circular road? It is understandable that it can topple but I feel it impossible that a moving car can skid. It is hard to imagine that a car would skid ...
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89 views

Energy of a damped oscillator

$$ E=\frac{1}{2}m\left(\frac{dx}{dt}\right)^2+\frac{1}{2}m\omega_0^2x^2. $$ This is the equation for the energy of a oscillator. The second term is the potential energy. Now, my question is, will ...
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96 views

Where does energy in a field come from?

Let us consider for example Earth's gravitational field. If we put a ball somewhere in this field, the ball starts to accelerate due to the gravitational force exerted on it. I understand the ...
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188 views

Why isn't $F = \frac{\partial \mathcal{L}}{\partial q}$?

If momentum is, $$p = \frac{\partial \mathcal{L}}{\partial \dot{q}}$$ and force is, $$ F = \frac{dp}{dt}$$ and by Euler-Langrange equations, $$ \frac{d}{dt}\frac{\partial \mathcal{L}}{\partial ...
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47 views

The superposition of force (or acceleration) configurations

My question is quite specific as it refers to this article but I hope that someone here could help me. I cite the relevant part of the article: ... The second example consists of gravitational ...
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1answer
85 views

Two masses attached by a spring [closed]

Suppose there is a system of two masses $M_1$ and $M_2$ connected by a spring with constant $K$ on a frictionless surface. What is the frequency of this system's oscillation? So I have fixed a ...
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2answers
196 views

What will be the velocity of a comet is falling to the Earth from infinity at the time of impact if Earth had no atmosphere?

What will be the velocity of a comet is falling to the Earth from infinity at the time of impact if Earth had no atmosphere? the comet is falling radially towards the earth. Will this velocity be ...
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1answer
90 views

Where does the potential energy go when mass is lifted out of Earth's gravitational field?

There is a finite amount of energy needed to be spent on a rocket or a rock that is taken out of the Earth's gravitational field. Lets suppose the rock is taken far enough to have no effect of Earth's ...
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395 views

Why do speed skaters use their right hand to accelerate?

I was watching the speed skating event, and was wondering, why do the athletes use their right hand while accelerating? If they want to increase the moment of inertia, then they should move the hand ...
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2answers
77 views

Animating an Acceleration Vector - Acceleration of object on a crested path in gravitational field

So I was reading in Chapter 3 of my textbook, Sears & Zemanksky's University Physics with Modern Physics by Young and Freedman, 13th Edition, and the discussion took us to a definition of the ...
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0answers
41 views

Determining impact velocity over long distances [duplicate]

Everything I have found concerning impact velocity from a given height deals with constant acceleration due to gravity. I would like to know how to work in varying acceleration into the equation. So, ...
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1answer
65 views

Heliocentric Worldview [duplicate]

Isn't the whole historic Discussion of Heliocentric vs. Geocentric Worldview just about a Calculation-Technique. I mean I could also choose my coordinate-center to be in the middle of Earth and setup ...
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2answers
89 views

Tangential acceleration in circular motion?

A lot of my problems have objects moving in circular paths with tangential and normal components of acceleration. If the tangential component is non-zero though, the speed is changing so the radius ...
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2answers
126 views

Two tensions in massless string

There should only be one tension in a massless string. But imagine this situation. Let a massless rope hang from a ceiling and two monkeys of different weights are holding on to the rope at two ...
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2answers
272 views

Angular momentum in a rod rotating around one end?

Sorry if I can't get straight to the point, I have to give a lot of details before I actually state the question. The formula for angular momentum is $L=I \omega$. If we look up $I$ for a thin rod ...
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1answer
220 views

Does total angular momentum of the Earth-Moon system include individual rotational angular momenta?

To calculate the angular momentum of a body we need to specify a point (or an axis?) from which to define the displacement vector $\vec{r}$, so that $\vec{L} = \vec{r} \times \vec{p}$. For a rigid ...
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0answers
34 views

Melting ice in a tray in space shuttle

We have an ice cube in a tray in a space shuttle. As the ice cube melts, the centre of mass shifts downward, so the tray should move downward to maintain the position of the centre of mass. Now, some ...
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2answers
155 views

Electrostatics kinematics equations (Coulombs Law)

If there are two similarly charged particles $Q$ and $q$ of masses $M$ and $m$, a Coulomb force is applied on each one (action-reaction). Suppose that $Q$ is stationary and we are shooting $q$ with an ...
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2answers
718 views

How to plot $(x,y)$ coordinate of projectile motion (with air-resistance)? [closed]

I am trying to plot a graph to show the difference in projectile motion when it has air-resistance and when it doesn't have air-resistance. I set the mass, $v_0$ and $\theta$ as constant I can plot ...
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227 views

Why meet at the center of mass?

If two objects of different masses are held at a distance $d$ and then I let them go, they will meet at the center of mass of the particle system due to mutual gravitational attraction My question ...
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1answer
151 views

Given moment about a pin and a roller [closed]

sorry to ask, have not been a able to find a similar question to mine. For this problem, given moment $M_2$, distances $a$ and $b$ My reasoning is that we have two support reactions and points A and ...
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1answer
117 views

How much weight can a person carry to avoid being blown over by wind?

I wonder if there is a certain amount of weight that I could carry in a rolling bag to help prevent me from being knocked over by the wind. I have balance problems and some lack of muscle strength in ...
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1answer
40 views

Understanding Normal Force Change

I know this has been asked around, my question is a bit more specialized towards my personal problem. If I have an object the magnitude of the weight is usually equal to the normal force, right? I ...
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1answer
283 views

Why doesn't the potential energy of any object equal 0

Consider a particle on the ground. This particle is raised by a force of magnitude $mg$ to a height $h$ above the ground. At this point, the work done on the particle by the force is $mgh$, which is ...
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53 views

Can I use the reduced mass principle in a spring-damper system?

http://hyperphysics.phy-astr.gsu.edu/hbase/orbv.html#rm I want to know, if I can use the reduced mass principle to solve a two object spring-damper system. In the books and webpages that I have ...
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3answers
98 views

Movement in outer space via Newton's law of every action has an equal and opposite reaction

What is more effective for travel in outer space ignoring all other factors like air radiation etc. I have a 10 kg bag of rice would I travel faster throwing the whole bag at once or throwing a grain ...
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1answer
84 views

Is there such a thing as instantly stopping?

I'm sorry if this is a stupid question, but I've never taken a physics class and I was curious about something. But anyway, my question is, is there such a thing as instantly stopping? For example, if ...
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3answers
487 views

Where is the energy lost in a spring?

Thinking about springs, and their extensions, I recently came to a confusion which I hope this wonderful community can help me solve. The question is this. When the block is initially attached to ...
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67 views

Stress calculations in a perforated paper

You have a sheet of paper (torn out of a good quality foolscap notebook) as shown above, and you start pulling it apart with both your hands (forces indicating by the blue arrows). Its difficult to ...
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2answers
202 views

Rod Falling on Frictionless Surface

A rigid rod with mass m is initially held at an angle with respect to a frictionless plane by a string. Then the string is cut. What happens to the rod? My intuition suggests that the rod should slide ...
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0answers
33 views

Mechanistic description of leverage

How would you describe how a lever is able to apply a large for to an object from only a small applied force without recourse to conservation of energy? Is there a purely F=ma type derivation? For ...
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1answer
107 views

Purely mechanical description of how gravity causes a gyroscope to precess

I know the vector equation that relates torque to moment of inertia and angular momentum. What I want to know is what physical mechanisms actually occur to keep the gyroscope from falling. Where is ...
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99 views

Where does an object get kinetic energy?

Where does an object "obtain" kinetic energy? I understand that an object often gets kinetic energy from another object. Where does the first object get the energy?
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264 views

What is the relation between General Relativity and Newtonian Mechanics?

What is the relationship of General Relativity and Newtonian Mechanics? Namely, which laws does GR replace of Newtonian Mechanics, and which laws of Newtonian Mechanics are incorporated into it. Or is ...
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1answer
95 views

Use Equations 1 and 2 to eliminate $T$ and show the expression for $f$ is given by [closed]

I am not quite understanding what needs to be done but I am assuming that I must combine the two equations and get rid of the variable $T$ in order to make this equation of $f$ below: (Note:These ...
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1answer
636 views

Confused about relating spring force to maximum distance

I keep working through this problem and getting the wrong answer: A spring with spring constant k is positioned vertically and then compressed from its equilibrium length by a distance Δy. A ...