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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Maximum range in projectile motion (elliptical path)

Elementary Newtonian mechanics tells us that if a projectile is shot at 45 degrees from the ground, and a downward gravitational field is acting on it, it will follow a parabolic path and achieve ...
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Constrained motion [on hold]

All speed shown are with respect to ground. Then we have to find the speed of block B with respect to ground. I tried it by two methods, but got different result why?
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Force needed question [on hold]

I am standing on a ladder 24 ft. in the air,The angle of the ladder is 65 degrees and I weigh 200 lbs and the ladder weighs 65 lbs ,How much force would be needed to lift the ladder off the ground,...
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Physics behind seemingly-impossible “rice bowl suction” Guinness world record? [duplicate]

By pressing a rice bowl on his abdominal muscles, Zhang Xingquan was able to create enough suction to pull a 36.15 tonnes heavy train for 40 meters Source: Guinness world records website. How does ...
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1answer
298 views

Question on Binet's equation

Is there a difference in Binet's equation when the force acting on a body is attractive and repulsive? I mean, if the force has a magnitude $F(r)$, is it Binet's equation always $$\frac{d^2u}{d\...
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1answer
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Expressing virtual force in terms of muscle contraction force

Two bodies connected with a hinge joint with axis in J. They also connected with a muscle at points M and M`. I’m trying to express virtual force Fv in terms of muscle force Fm acting at the point M ...
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2answers
29 views

Work and energy example [duplicate]

The normal definition of Work, as far as I have read, is: Energy is transferred through work. But I just heard an educationist state this example, where there is a weightlifter who keeps up a huge ...
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1answer
88 views

Sliding blocks problem

My first post here, so I apologize if this is duplicated elsewhere. It IS a "homework" problem, but it's public domain, a posted exam with answers... http://www.mun.ca/physics/undergraduates/...
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Force applies to sphere not on center of mass?

Is this true: When force is applied to a sphere NOT on center of mass (COM) then the sphere will move the same way as when force is ON center of mass, because the sphere is symmetric in every ...
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48 views

Non-diagonalisable system of ODE from structural mechanics

Consider a basic mechanical system driven by the second order ODEs $$ \mathbf{M\ddot{x}+D\dot{x}+Kx=0}$$ where the mass matrix $\mathbf M$ is positive definite; no specific assumptions other than ...
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2answers
38 views

Verifying directions of forces during pure rolling?

Let us take a cylinder on a rough horizontal surface. The cylinder undergoes pure rolling A vertical downward force acts on the cylinder to produce a clockwise rotation. The point at which it acts ...
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1answer
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Equilibrium of rigid body [closed]

A uniform beam $AB$ of length $2l$ rests with end $A$ in contact with rough horizontal ground. A point $C$ on the beam rests against a smooth support. $AC$ is of length $\frac{3l}{2}$ with $C$ higher ...
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1answer
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Projectile question doubt [closed]

A hunter wants to shoot a monkey with an arrow by launching the arrow at a speed $v_0$ at a distance of $L$ from the base of a tree of height $H$ on which the monkey is sitting. Now on watching the ...
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1answer
159 views

Is the double pendulum an example of a strange attractor?

Imagine a pendulum to which is attached another one (not necessarily the same length). Does this pendulum, when you let it go (which can be done in many ways but let's keep the total potential ...
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0answers
41 views

How does the bowling computer know I'm right handed? [closed]

I went bowling the other day and after I rolled my first ball I was suprised it was written on the screen that I was "right-handed". How was that figured out? My first guess is that there is ...
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2answers
103 views

Work energy theorem explanation

So there is this problem in my head, it may seem very simple, but I need an answer. The problem is, we have some object, and we apply a force by our hands with a constant speed from a position (1) to ...
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2answers
56 views

Why there is an extra componet of force in this Equilibrium state?

I have a question about the forces on a body at equilibrium. Look to this image: here i draw a man standing with a pen on earth. And I think that I draw all possible forces on it. They are as ...
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2answers
90 views

Can energy conservation be derived from Newton's Laws?

Can the idea of energy conservation be derived from Newtons's laws? From inspection of his laws you can vaguely discern a relationship but I want to know of you can manipulate his laws to prove it. ...
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3answers
358 views

Are Newton's laws followed in non-inertial frame of references having all their objects and observer moving with same acceleration?

Consider a hypothetical scenario. In our universe there are two merry-go-rounds 1 and 2 and a distant planet. There is no other object having mass. There is a robot X on the planet. There are two ...
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2answers
116 views

All reference frame are inertial? Where is the flaw in reasoning?

This is my first post here. I have a line of thoughts which might be wrong but I couldn't find the error. Suppose we have a point mass subjected to an arbitrary force $F$. In the lab reference frame ...
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1answer
43 views

How to calculate the linear momentum on a dumbbell? [closed]

In this picture there is a dumbbell and a mass in motion that hits one of the masses of the dumbbell. Now the problem is I have to find the velocity of the CM and the rotational speed around the CM. ...
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1answer
45 views

Is this differential equation (for damped & driven physical pendulum) physically valid?

Following is the equation of motion for a physical pendulum which is damped and driven by a force of frequency $f$: $$\frac{d^2 \theta}{dt^2} + b \frac{d\theta}{dt} + sin(\theta) = Tsin(2\pi ft)$$ ...
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What would be the craziest (but still plausible) plan for launching a small payload to the moon? [closed]

I wonder what would be the cheapest possible (that means cheaper than anything else that's out there already) to "just" launch a small payload (like a ball less than a kilogram) and crash it somewhere ...
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3answers
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3
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1answer
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Why does the beam in a weighing balance get tilted proportional to the weights added to each pan?

I'm talking about a beam balance(a simple weighing balance with a beam and two pans hung on either side) As answered in a previous question, the beam comes back to the original position when one ...
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1answer
229 views

How does ground interact with a box rotating around its corner?

I have some questions about how forces $F$, friction force $F_{friction}$, and normal $N$ interact in order to the box below to turn (clockwise) about the red corner, without sliding. The force $F$ is ...
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1answer
43 views

Force required to rotate around an axis [closed]

So I have a rather simple physics question that I am not sure where to begin with. I am designing a dumper and I need to figure out the amount of force required to rotate and lift it around a bearing. ...
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1answer
320 views

Derivation of Universal Variables

Does anyone know of link to the derivation of the Universal Variables? This is in regards to Kepler's equations. The Wikipedia link didn't have enough information for me, and the Colorado page doesn'...
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6answers
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Confusion with Newton's third law

“Every action has an equal and opposite reaction.” I have a query about the word every in that sentence. Suppose we have two objects A and B. A pushes B with a force of 5N and B will push A with a ...
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2answers
55 views

Energy Stored in Spring [closed]

Area Z represents the energy stored in the spring when it is stretched to a length L I am trying to understand why this is so: $$E = \frac{1}{2}kx^2$$ Here, $x$ is the vertical side of triangle $Y$...
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260 views

Centripetal and centrifugal force

If a stone is rotated with the help of a rope, then both centripetal force and centrifugal force will be liberated. The magnitude of that forces are same, but direction of them are opposite to each ...
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1answer
37 views

Acceleration in full-swing pendulum

Consider a $360^{0}$ swing pendulum with a massless rod. If I start it from the position of unstable balance, at the very top of the circumference, according to the conservation of energy, its ...
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1answer
50 views

What is the degree of freedom of pure rolling motion?

A cylindrical body is pure rolling, what will be the degree of freedom for it? I am confused between 2 and 1 if slipping occurs than it has 2 but in pure rolling there's no slipping so what will it ...
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Information about newton's third law

Well I am still small student of physics, but as far as I know, Newton's Third Law states that, "For every action there is equal and opposite reaction." Now let me tell you how I understood ...
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Few questions related to Tension

I am struggling with the concept of tension in a rope. Below specific questions. I am understanding tension to be an elastic force between rope molecules. If so, is it fair to say the net tension ...
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1answer
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Simple Conservation of Energy Question

Deduce that the speed $V$ with which the bullet strikes the plasticine is about $160 \ m/s$ Using the conservation of energy, I equated the kinetic energy of the bullet to the potential energy of ...
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Dropping Objects on Whilst Moving Seen by an Outside Observer [closed]

As shown in the image, it seems obvious to me that the answer would be $D$. However, the answer is $C$. What is flawed in my conceptual understanding?
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1answer
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Torsional spring and Euler angles

I have a question about the moments generated by torsional springs. Consider an inertial reference frame A and a body fixed reference frame B. The frames are connected by 3 rotational springs acting ...
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2answers
49 views

System rigidity

What is the meaning of system rigidity in mechanics? I can't understand how to classify the system as rigid or not, and what is the effect of rigidity on the whole system. If you know anything about ...
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4answers
69 views

When a person bends forward, does normal reation force change as a component of his weight is applied in torque?

My thoughts :i read that normal reaction is equal to the weight of the person in the case above as the effective vertical force in the system is zero.but im confused cuz a component of the weight is ...
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6answers
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Newton's third law and punching a glass or a feather

According to Newton's third law, action force equals reaction force in terms of magnitude. When I punch a glass, the glass punches me back. If I exert a greater force on the glass, it will break. ...
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7answers
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Ball flying towards me or me flying towards ball

Suppose a ball is flying towards me at a speed of 10m/s and that, on impact, I feel "x" amount of pain. If, instead, it was me flying towards the ball at the same speed, with all other conditions ...
4
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3answers
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Tension in the string [closed]

In the following diagram, what's the force that's acting on $m$, the Tension in the string? There is no friction between $M$ and the ground but there is between $m$ and $M$ and I need to find the ...
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2answers
96 views

Finding acceleration in a pulley system

In the above system, mass A is accelerating at $a$ upwards. The question then asks to find the magnitude of mass B's acceleration, in terms of $a$. I know that throughout the massless string, the ...
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4answers
129 views

How to apply a force vector to a position vector?

A particle is present in the two dimensional space. It's position is given by the vector: $$x = \begin{pmatrix} |x| \cos(\theta) \\ |x| \sin(\theta) \end{pmatrix}$$ It experiences a force of: $$ F = \...
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2answers
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Point object, Kinematics

I am very new to physics. This evening, I was reading about the concept of objects to be considered as point objects under some circumstances. And I was trying to think of circumstances under which ...
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1answer
28 views

Outbalancing vibrations

Consider a ship vibrating in the fundamental/principal/first symmetric mode shape (similar to that of a Bernoulli-Euler beam), induced by the main engine (similar to that of a vibration shaker). I ...
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2answers
196 views

Breaking Newton's 3rd Law?

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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