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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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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64 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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1answer
58 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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252 views

Power as a Function of Distance

I am interested in trying to understand the meaning of the integral of power with respect to distance. In the case of force, we have the two formulae: $\int F \, \operatorname{d}\!t = \Delta p$ and ...
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1answer
117 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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113 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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2answers
153 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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2answers
184 views

Can a car skid while moving in a circle? [closed]

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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1answer
144 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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1answer
65 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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2answers
470 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
155 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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1answer
138 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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2answers
254 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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0answers
44 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
80 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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1answer
283 views

Is There Any Work Done By Normal Reaction Force even if point of application of force is not getting displaced?

Suppose that I am standing on the ground and I suddenly jump and rise up to any certain height.So accordingly I would have gained some speed i.e. Kinetic Energy during the process of jumping.According ...
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2answers
387 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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0answers
43 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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3answers
290 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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2answers
3k 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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1answer
686 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 ...
2
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1answer
240 views

A bumpy ride on a bike?

While riding a bike at a higher velocity, I go over the speed breakers (Hump) I get jumped over the bike for a certain height. How do I calculate this height of jump with respect to the seat of the ...
3
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1answer
201 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 ...
2
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1answer
51 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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3answers
205 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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0answers
84 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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1answer
257 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 ...
2
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2answers
429 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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3answers
1k 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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0answers
101 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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1answer
375 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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40 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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0answers
521 views

What is the maximum tension in N the string can support [closed]

I have a length of string and I want to know the maximum tension the string can support. I tie one end of the string to the ceiling and the other end to a glass of mass 100 g. The glass is ...
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1answer
349 views

projectile power with air resistance [closed]

I need to get the x/y values of a fired projectile given the angle of the initial power, and air resistance. The formulas I have are $$V_x=V_o \cos\theta$$ $$X=V_o \cos \theta t$$ $$V_y=V_o \sin ...
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1answer
43 views

Proof about Newton: Homework [duplicate]

a mass hangs from three ropes (as shown in the Picture) can someone pleas help me with this?
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2answers
5k views

Physics: Tension on a string from a system [closed]

Ok, I am stumped by this question: In the system in the diagram below, block M (15.7 kg) is initially moving to the left. A force F , with magnitude 60.5 N, acts on it directed at an angle of 35.0 ...
2
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1answer
172 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
1k 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 ...
2
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1answer
154 views

Velocity of hitting the ground when falling forward

A friend of mine fell while he was snowboarding which led to a discussion. He mentioned that, in general, if your center of mass is traveling at a certain velocity, and you fall forward, your head ...
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3answers
5k views

Why does the tension on the pulley in an Atwood machine not equal $(m_1 + m_2)g$?

Consider the following simple Atwood machine with an ideal pulley and an ideal string According to my textbook, the tension on the clamp that holds the machine to the wall equals $2T$. I don't ...
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1answer
96 views

Mechanical system modeling

I have a mechanical system and I need to model in differential equations I tried to model the mass $M_1$ and got this $m_1\displaystyle\frac{d^2\,x}{dt^2}=F-K_1(x_2 - ...
4
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1answer
296 views

Question about gravity in 1 dimension

Consider 2 pointmasses in 1D space. More specific ; object $A$ with mass $m_a$ and object $B$ with mass $m_b$. $A$ and $B$ are a distance $d$ away from eachother. Let these pointmasses $A,B$ have no ...
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0answers
1k views

Damping ratio and damping coefficient of two objects connected by spring

There are two objects m1 and m2 connected by a spring and a viscous damper (e.g car body and wheel connected by spring) From wiki: $\zeta ={c \over 2{\sqrt {mk}}}$ ζ is damping ratio, c is damping ...
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4answers
4k views

Does an athlete's proficiency at luge depend on his mass?

I was watching the men's luge ride with my dad. My dad said, the mass of the athlete must be at an optimum level so that he wins. I said, his volume should be minimum, but it has nothing to do with ...
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10answers
23k views

Why is acceleration expressed as m/s/s?

I'm a philosophy student (I, regrettably, don't know calculus or much physics). Last year I spent some time learning how work, power, speed, velocity, energy, force, and acceleration relate. But I was ...
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2answers
270 views

Higher moments of the kinetic energy operator in QM

I have set myself the task of studying the kinetic energy $T$ in a quantum mechanical system. For the latter, I use the simple case of the Hydrogen atom in the $n=1$ state. Then the wave function is ...
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1answer
78 views

Regarding the centrifugal force in a 3-body system

In our lecture about general mechanics, we have treated the simplified 3-body system consisting of the Sun, the Earth and the Moon. We assumed that the moon does not have any influence on the Sun or ...
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2answers
202 views

Is rotational motion conditioned to a central force?

We know rotational motion as a combination (a resultant) of two effects the tangential velocity and a centripetal force. Does rotational motion turn into linear motion at the same instance this ...
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3answers
180 views

A reference frame must be non-moving?

I'm tough in school that a reference frame must be non-moving; For example if I take as reference frame the waves of the ocean, i will have the impression that i'm moving, but I'm not. But if movement ...