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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42 views

Projectile motion problem [closed]

A perfectly elastic ball is thrown against a house and bounces back over the head of the thrower. When it leaves the thrower's hand, the ball is $2\text{m}$ above the ground and $4\text{m}$ from the ...
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0answers
9 views

The ratio of equators radiuse to polar radius

I want to calculate (Re/Rp) where (Re) is the rediuse of earth in the equator and (Rp) is the rediuse of earth in poles. I want to use newtons laws, the eqution of gravity and centripetal force ...
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2answers
47 views

What objects' masses do we need to take into account when calculating force?

In the following problem: A steam engine of mass $3\times 10^4\ \mathrm{kg}$ pulls two wagons each of mass $2\times 10^4\ \mathrm{kg}$ with an acceleration of $0.2\ \mathrm{m/s^2}$. Neglecting ...
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1answer
56 views

Which ellipse does the Earth's semi-major axis refer to?

In Wikipedia the semimajor axis of the earth is reported to nine digits of accuracy (nearest kilometer), and the eccentricity to eight. But to which ellipse exactly does that apply? Sun-at-the-focus? ...
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1answer
38 views

Friction between two bodies placed one above another [on hold]

I'm recently facing a bit confusion regarding the friction between two bodies. Suppose there's two bodies, one placed on another. There is frictional force $ f $ between the base body and floor and ...
0
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1answer
11 views

Clarification needed:Projection Or Whole Length to be considered during integration

Sometimes in magnetism,electrostatics,friction problems when a force is acting over a curved we usually take the net projection of the curved path as the distance(to avoid integration).But it certain ...
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1answer
37 views

Paradox of potential energy of gas molecule

We know that when water is heated at its boiling point, it will become vapors. Then because there is no change in temperature, the heat supplied will be transferred to the potential energy of the ...
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2answers
21 views

Collision of Inelastic ball above the ground

An inelastic ball of mass $m$ is dropped from a height $h$ above the ground and at the same time a second ball of mass $m_1$ projected vertically upwards to meet the former. Show that in order that ...
1
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0answers
38 views

3D Simulation Software

I need a software capable of simulating the physics of a car going off a ramp. This is a stunt that I will be attempting and looks like the following: A car, going off a curved ramp, doing a barrel ...
1
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2answers
58 views

Appearance of the Jerk Term in Dynamics of Mass-Spring-Damper System

I am coming from the computer science territory and have not a long trace in mechanics. My background in derivation of the system dynamics could be summarized with utilization of the ...
1
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0answers
51 views

Friction related question [closed]

A uniform chain of mass $M$ and length $L$ is hanging from the table. The chain is in limiting equilibrium when length $l$ of chain overhangs. It is slightly disturbed from this position. Find the ...
2
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2answers
80 views

Reaction due to gravity

There is a reaction to the gravity of the earth on us but the earth does not move due to its huge mass. But what if I combine the weight of all humans and other things on Earth? Is it not enough to ...
2
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1answer
41 views

Paradox about the efficiency of a thermal engine

Based on that, the algebra calculation is correct. But it seems confused to me. Even though the overall efficiency reduces, it is still useful, isn't it? From the same amount of energy we can ...
0
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1answer
42 views

Mechanics question don't understand answer

A space platform in the form of a thin circular disc of radius a and mass m (flying saucer) is initially rotating with angular velocity w about its symmetry axis. A meteorite strikes the edge of the ...
3
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3answers
288 views

Why Can a Skydiver Hit the Ground and Be Killed? [duplicate]

This is a follow on question from Physics SE Question "Can a Skydiver Land On a Large Slide and Survive?". User Steeven gives this answer here. User Dargscisyhp asks: What is it exactly that ...
0
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1answer
36 views

Question about solving Newton's laws' problems [closed]

A questions from my textbook asks me what the force by the pulley on the roof is. In order to answer the question, need I consider those objects hanging from both sides of the rope, or need I only ...
0
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2answers
47 views

Confusion about the resonance

I get confused with the concept of resonance. Many materials suggest that in order to achieve resonance, the system must undergo simple harmonic force ($F=F_0\sin(\omega t)$), and at the natural ...
0
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1answer
16 views

Reflection of a moving ball

We know that when a ball hits a wall at an angle alpha, it will bounce off with the same angle, just like the mirror rules. But why does it happen exactly? Based on what theory does it happen? When I ...
0
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2answers
49 views

What should the brake force in this problem be? [closed]

Alright so I think I know how to do this but I require help in calculating what acceleration would be in terms of some sort of friction coefficient. So model a particle going down a hill. The slope ...
0
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1answer
39 views

Total energy loss of a sphere as it falls through a distance $h$ [closed]

A block of mass $M$ is placed on a rough horizontal table. A string attached to the block runs horizontally to the edge of the table, passes round a smooth peg, and supports a sphere of mass $m$ ...
0
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5answers
98 views

Pulley system: how can tensions be equal throughout a entire rope if the weights on opposite ends are different? [duplicate]

More weight means more pulling force, and thus more tension force. Like this answer says, however much force you pulling with is equal in magnitude to the tension force. If that is case, how then ...
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2answers
32 views

Distance traveled from displacement

I am currently reading a book called Physics for Scientists and Engineers by Serway. While reading the chapter about 2-dimensional kinematics, I asked myself a ...
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2answers
38 views

Strain Rate Tensor

I was going through Schaum's outline for Continuum Mechanics and came across the strain rate tensor. As the strain rate tensor, when represented geometrically, shows the deformation that is happening, ...
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0answers
25 views

Energy specific question [duplicate]

I am math undergrad, so I am sorry if my question is trivial here. Given a equation for the potential how do you determine if the specific system is conservative ? can you determine by adding K + V ...
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2answers
116 views

Faster-Than-Light Communication using Entangled Photons

Based on my understanding of the “Double-Slit Quantum Eraser Experiment”, documented here: http://grad.physics.sunysb.edu/~amarch/, it seems that Faster-Than-Light communication is possible. Of ...
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2answers
103 views

How did physicists arrive at conclusion that the product of mass and velocity is equal to momentum?

How did physicists arrive at conclusion that the product of mass and velocity is equal to momentum? What is the intuition behind $p=mv$? I had trouble finding any sources that state the actually ...
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2answers
53 views

Simulation of a simple robot [closed]

I'm a programmer and I'm working on a simple robot simulator. Of course, the most important part of this simulator, is the physical simulation of the robot. Unfortunately, I have a little knowledge ...
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1answer
27 views

What are the limitations of using instantaneous axis of rotation? [closed]

I know when the body rotatates as well as translates IAR or ICR shouldn't be used but I am not able to understand why?
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0answers
20 views

Calculating atomic forces from total force and torque on molecule in molecular dynamics (MD)

I guess this problem applies to any body that is composed of a small number of particles, but for the sake of simplicity and concreteness, let's consider a classical model of a molecule consisting of ...
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2answers
20 views

Some confusion pertaining to direction of static friction on stationary object

Consider a stationary object of mass $m$ on a horizontal table. Since the object does not move relative to table, $f_s=0$. So it seems that we first consider $mg$ and normal reaction force,$N$ ...
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3answers
135 views

Why can't we find a true inertial frame?

From one book, I read that if we release a ball horizontally on earth, its velocity does change in very accurate observations. If we track its motion, we get full information of its motion (incl. ...
0
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3answers
61 views

Determine direction of friction on a block held stationary against a vertical wall [closed]

A block of mass $m$ is pushed up against a wall and held stationary by a force $ F$ that makes an acute angle $\theta $ with the horizontal. May I know how to determine the direction of the static ...
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votes
1answer
31 views

What is the minimum acceleration that stops the rod from sliding in the frictionless surface? [closed]

What should be the block's acceleration 'a' such that the rod present inside, inclined at at the angle 'theta' and mass 'm' will be obstructed from sliding down. From car's frame of reference, a ...
0
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1answer
18 views

Acceleration of ball released from height H on a circular fixed wedge at its lowest point?

I've been facing a conceptual problem for quite some time. Suppose there is a fixed wedge.A ball of mass $m$ is released from a height $H$. The coefficient of friction on the surface is $μ$. ...
3
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2answers
75 views

Acceleration of a ramp

If we have a ramp and a block on it, and if all the surfaces are frictionless so both the the ramp and block can move. Is the normal force different from the time that ramp is not moving? If yes can ...
0
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0answers
19 views

Best learning of gyroscopic motion? [duplicate]

I crave to learn the nitty-gritty of attitude dynamics - namely I want to get really up close and personal with angular momentum, gyroscopic motion, non-inertial effects. I'm looking for a resource ...
2
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3answers
131 views

How can I calculate whether a shelf is strong enough to support a falling cat?

I'm building some shelves for my cat to climb on. The highest position the cat will be is 2 meters above the next shelf. The cat has a mass of 6.5kg. The shelf has a maximum load of 20kg. Using ...
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2answers
33 views

Weight added to truck [closed]

If weight is added to the back of a dump truck does the height of the truck decrease in direct proportion to the weight added - does weight added equal height decrease?
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2answers
100 views

Hooke's Law and Simple Harmonic Motion

Can anyone explain how the following formula is derived and what it means? $$x'' = -n^2x $$ I was reading through my high school physics textbook and I stumbled upon a section on Hooke's Law. It says ...
0
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1answer
61 views

Shape of water jet

Suppose you are shooting a water jet in a vacuum vertically onto a flat plate in a gravity-less room. The jet makes a right angle to the plate and water is assumed to be incompressible. The mass ...
1
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1answer
82 views

Acceleration orthogonal to movement direction

I've been told that acceleration orthogonal to an objects movement direction doesn't require energy. Thus when a satellite goes around the earth, the change in direction caused by gravity doesn't use ...
0
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2answers
31 views

Rod partially handing off edge of table

A uniform rigid rod of length $L$ lies at the edge of a frictionless table so length $x$ of the rod rests on the table and the rest is beyond its edge. Intuition suggests that the rod will stay like ...
1
vote
1answer
33 views

Rocket velocity during fuel burn [closed]

I know the formula for the velocity of a rocket after the on board fuel has been used up: $$ \Delta v = v_{ex} \ln\left( \frac{m_i}{m_e} \right) - gt $$ where: $v_{ex}$ is the exhaust velocity ...
0
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1answer
38 views

How to understand newton (unit of force)?

Simple question here for all of you, but I just wanted to form a mental image of the concept. I know the definition, but it's not 100% intuitive to me. So, I imagine 1 newton as force that I apply on ...
0
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1answer
39 views

Explanation about friction force directions of two moving bodies in contact

can someone explain me why in this scenario (picture below) we have a friction force Ftr12 in the same direction as movement (left part of the picture, case 1 ) and how these directions of friction ...
-3
votes
6answers
110 views

A contradiction statement to $F=ma$ [closed]

If I thrown an object of mass 1 kg up in the air it will always fall with an acceleration of 9.8m/s. If I throw it very high up in the sky, it falls with a greater force as compared to if i throw it ...
0
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2answers
43 views

How did people discover the conservation of mechanical energy?

I want to write about the history of energy, and am focusing on mechanical energy at the moment. My question is: Can I attribute the conservation of mechanical energy to the power of maths, ...
2
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0answers
16 views

Creating a structural dynamic model using only modal test data

Short version: Suppose I excite a vibrational response in some structure and measure its mode shapes and natural frequencies. Is it possible to create a structural dynamic model of the structure ...
2
votes
3answers
94 views

Solving the two body problem numerically

I'm trying to solve the two body problem numerically, setting up $G$, $m1$ and $m2$ to be equal to 1. then I located each mass on positions -5 and 5 respectively along the $x$ axis and gave them both ...
1
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1answer
82 views

Newtonian motion of a particle confined to a smooth surface

Recently, I've been considering a model wherein a lone particle with constant mass m is confined to a surface $F$: $\mathbb{R}^m \to \mathbb{R}^n$ , where $m < n$. I declare this surface to be ...