# Questions tagged [newtonian-mechanics]

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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### Sign Problem When Dealing With Quadratic Air Resistance and Gravity

While dealing with an object falling vertically, and subject to quadratic air resistance, an equation of motion that is often presented is \begin{equation*} m\dot{v} =mg-cv^{2} \end{equation*} In ...
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### Why a ball doesn't stop when it collides with a wall?

If a ball collides with a ball of same mass the first ball stops and the second ball gets the velocity of first ball.The first ball stops due to the reaction force acting on it. But when a ball ...
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### The radius required for an object to fly out of a cone in circular motion

So I've in encountered this problem. We need to find the critical radius beyond which the cricket( Jimmy) slides outward. So far I have the following vectors From this point on I'm lost. I ...
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### Velocity of charged particle when releases in front of conducting plate

I want to find speed of charged particle q when it is released from certain distance from plate and comes to a distance d, due attraction by induction my doubt is wouldn't the force on charged be ...
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### Is the slotted mass responsible for the centripetal force in vertical circular motion?

Is the slotted mass responsible for the centripetal force in a vertical circular motion in this particular experiment? I want to do the following experiment, where I hand spin a mass (red) that is ...
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### Ball motion in water

I am analyzing a video of a ball falling in water with tracker. The ball falls in a free fall for few seconds before it reaches a glass of water. The ball goes down till 3/4 of the glass, then stops ...
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### Trajectory in Pool Game

How to solve it ? In a game of pool, calculate the trajectory of the cue ball after it strikes the object ball. The coefficient of kinetic friction between cue ball and table is $\mu_k$. Assume the ...
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### Acceleration of human accelerated into vacuum

How would one calculate the acceleration of an object released into a vacuum? Imagining you have a Person in an airlock and that airlock suddenly opens depressurizing instantly from 1atm to 0 how ...
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### Why does limiting friction have to act when a block tied to a wall is pulled?

A block lying on a rough surface, is connected to a wall by a mass less, inextensible string and an unknown amount of force is applied to the block opposite to the side of the wall. Now, if it is ...
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### Prime numbers in physics of falling and collision [closed]

A small ball moves at a constant velocity v along a horizontal surface and at point $A$ falls into a vertical well of depth $H$ and radius $r$. the velocity of the ball forms an angle $\theta$ with ...
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### “Tribo-Fatigue” Is this fringe pseudoscience or actual science?

Recently, while reading the wikipedia article on entropy, I came across "Tribo-fatigue entropy" in the interdisciplinary applications section this section seemed suspicious to me; even though there ...
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### What is minimum value of acceleration a at which the cylinder starts to rising up the inclined surface is? [closed]

I can solve this question from non inertial frame. Can anyone help me to solve it from inertial frame of reference.
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### Why are inclined push-ups harder?

I came up with a random question which looked simple, but I can't work out the answer. The question is, why are inclined push-ups harder? And by inclined push-ups I mean push-ups with your legs on a ...
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### Infinite Speed of Light

I recently watched a video that stated that Newtonian Mechanics assumed an infinite speed of light. That same video, "PBS Space Time: The Speed of Light is Not About Light", stated that if the speed ...
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### Three pulley system with middle pulley lower than the other two [closed]

I have a pulley system with 3 pulleys. Just wondering if this system is adding to the weight that is being lifted? It feels like it is increasing the weight, but i am not completely sure. I do not ...
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### Why does a person float rather than staying in the elevator's floor in a free fall?

Many people have asked online why does a person float on a free falling elevator in earth. But my question is why doesn't a person just stay in the elevator's floor when the elevator is in a free fall?...
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### Can I say $F_s=-kx$ is also equals $F=ma$? [closed]

Is $F=ma$ a general formula for all cases in the physical world? or Is it only limited in linear motion?
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### Clarification of Ehrenfest theorem

The page on Ehrenfest theorem in Wikipedia(https://en.wikipedia.org/wiki/Ehrenfest_theorem) says- "Although, at first glance, it might appear that the Ehrenfest theorem is saying that the quantum ...
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### When you have engine at idle and turn your car, where does the kinetic energy go?

When you turn the front wheels to the right for example, your car will tend to continue in its original forward direction. However, there is friction between the wheel and the ground that prevents it ...
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### Force generated by ball screw linear motor?

Say I have a motor with a certain amount of torque, $T.$ It is turning a ball screw mechanism like this . Say, I mount something on the nut, I want to calculate the mass of an object I can lift ...
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### Pressure at the foot of ocean waves?

If I'm surfing a 100 ft wave and temporarily dip my finger into the water near my surfboard ..would it experience the pressure due to the whole water column or is there some other principle of ...
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### I do not know whether I solved this correctly. Can anyone help me? [closed]

An object moving with constant acceleration travels distances 20m and 24m respectively in 3rd and 4th second of its motion. Find the initial velocity and the acceleration of the object. My initial ...
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### Derivation of Kepler's laws

How can analytically be derived the Kepler's laws? I found some extremely synthetic equations which from the Newton's laws (in particular $\mathbf{F} = m \mathbf{a}$) tried to obtain the Kepler's ...
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### Calculating wheel loads on a motorcycle / car / bike

I have found many pictures on how to look at the forces here, for example THIS. It bothers me that this doesn't seem to be correct. Since the wheels turn (and the slipping of the tyre is about 20% at ...
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### What's the height at which a rocket has to start its engines to land? [closed]

Suppose you have a rocket on a trajectory not far from the atmosphere-less surface of a planet. Also suppose the rocket can produce thrust without lowering its mass and the gravitational constant of ...
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### Projectile degree horizontal [closed]

a large cannon is fired from ground level over level ground at an angle of 30 degree above the horizontal.The muzzle speed is 980 meter per second neglecting air resistance, the projectile will travel ...
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### Time period of Simple harmonic motion (spring has mass) [closed]

$m_s$ is the mass of spring and $k$ is the spring constant. If the block of mass $m$ is initially at mean position, find the time period of Simple harmonic motion using energy method. I am in 12th ...
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### Can classical mechanics be axiomatized in a way similar to what is done in Euclidean geometry?

Can classical mechanics be axiomatized in a way similar to what is done in Euclidean geometry? If we took Newton's laws as axioms, what other axioms would be needed to deduce all of classical ...
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### Where does the centripetal force come from? How to calculate?

When a bucket filled with water rotates, the water surface will be parabolic( I mean the water is rotating and the water surface is parabolic). Where does the centripetal force of a particle of water ...
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### Relative Motion of Airplanes and Carts [closed]

A plan travelling north at 100.0 km/h through the air gets caught in a 40.0 km/h crosswind blowing west. This turbulence caused a beverage cart to to brake free and begin rolling at 20.0 km/h toward ...
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### Newton's Second Law at variant mass system [duplicate]

How can we calculate the acceleration of a function 't'(time) if the exert force 'F' is constant and the mass of the material changes as a function m(t)=m+at? Using the Newton's Second law.
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### Does mass matter at all for kinematics vertical questions w/o friction?

This is the specific question w/o information on mass given, I think here is not enough info. A block and a sphere are each released from rest at the top of an incline from the same height. The ...
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### Accurate mathematical description of angular acceleration?

My physics textbook says that angular acceleration is the derivative of angular velocity, but I think that this isn't accurate. For example let's imagine that a block is tied to a rope that passes ...
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### Does “inflation” eliminate the requirement that the big bang distributed an infinitely dense kernel of mass?

My admittedly limited understanding of the big bang is that it was an event that expanded spacetime itself along with the kernel of infinitely dense material that coexisted at the moment of the big ...
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### Why does normal force exist on an object traveling at the sides of a vertical circle?

By Newton's 3rd Law, every action has an opposite and equal reaction. When the object is at the point depicted in the circle, we know for sure that gravity is pointing straight down. Then, if a normal ...
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### How to calculate position of a car based on the steering wheel radius

This is sort of an elementary question and if it doesn't belong here please remove. I am trying to write a simple program to simulate a car moving. My question is, suppose I know the wheelbase and the ...
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### Why are some energies dependent on reference frame, and some are not? And why is transfer between them possible?

For example the chemical energy of a kilogram of gasoline is 44-46 MJ/kg. It is only dependent on its chemical structure, which stays the same, whether the gas tank moves or stays still relative to ...
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### Significant figures in meter scale

A meter scale is graduated at every milimeter . How many significant digits will be there in a length measurements with this scale
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### Time period on a moving wedge [closed]

This question is based on simple SHM but I am stuck in this question. My approach: I realised firstly that we cannot assume gravity free space because then the wedge might move in any direction which ...
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### How force affect the objects that we apply on? [duplicate]

Why do things get accelerated rather than do a moving at constant speed when we apply a force on them? How my force affect the object at atomic level? Does it increase the kinetic energy of atoms ? If ...
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### Explaining The Unbelievable Pendulum Catch

What would be a theoretical explanation of an "ideal" 14:1 mass ratio in this experiment, also demonstrated in this video? The experiment ties one nut to one end of the string and 14 nuts to the ...
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### Energy lost as heat and sliding friction [closed]

The answer to this problem is given at the back of the book as 5.0 J. The book is for olympiad preparation (from india).I borrowed it from a friend.Its name is 'pathfinder by arvind tiwari and sachin ...
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### Simple Harmonic Motion with an unknown mass distribution [closed]

I've been trying to control a Segway robot using controllers and a bond graph model (I'm modelling it as an inverted pendulum on a cart), and I am not quite sure how to determine the moment of inertia ...
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### Why mirror production imitates human hand motion?

In this video (timestamp in URL), it shows how mirror production machines imitate the random action of human hands when rubbing two surfaces together: https://youtu.be/ABRysNzcdvw?t=1068 Why does it ...
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### Quite an interesting problem on friction and springs [closed]

the answer to this problem is given at the back of the book as 5.0 J The book is an olympiad preparation book from india. i borrowed it from a friend. its name is 'pathfinder' anyways..my answer, to ...
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### University Exam question about “Systems of Particles” [closed]

I am doing an old exam where I encountered this question, and no matter what I try to throw at it. I cannot solve it (This is from the Chapter "Systems of Particles, which composes of Center of mass, ...
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### The work done when stiffness constant for a cord is changing continuously? [closed]

Is my solution to the following problem correct ?..the answer at the back is 132.25 J while my answer is 138 J.I really think that this time the book is wrong (it is an Indian book for physics ...
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### Conservation of energy of 2 identical Rolling Disks with and without friction

My physics book claims that if two identical disks moving at the same velocity travel up nearly identical hills, with the second hill not having friction, then the disk rolling up the first hill will ...