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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70 views

Maximum acceleration for a vehicle [closed]

I'm in engineering school and we have a project: we have to build a amphibioues vehicle; I'm looking for a formula. Our vehicle has to go as far as possible with its unique source of energy, a ...
1
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2answers
128 views

Collision of two satellites

In a theoretical situation in which two identical satellites travelling around the Earth in opposite directions collided head on so that there velocities relative to the earth both became 0, would ...
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1answer
48 views

Derive Equation For a Cantilever in SHM

I am currently investigating how a hacksaw blade's time period of oscillation changes when I add mass to the end of it or when I change the length it is clamped at. I found the following equation ...
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2answers
79 views

Why is momentum conserved in inelastic collisions? How is it related to momentum-impulse theory?

First of all I want to mention, that I've found many questions around this site and in other websites dealing with my question; however, I don't think they answer my question fully. So I am here to ...
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0answers
31 views

imbalance calculation something with f m r in calculation [closed]

A road wheel has a mass of 10kg. It is found that its centre of mass (or gravity) is offset from its centre of rotation by 2mm. Calculate the out-of-balance force acting on the wheel when the vehicle ...
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3answers
110 views

Coriolis force on bullet vs airplane

Why do airplanes experience negligible Coriolis force while bullets experience the Coriolis force in long range shooting, even though the mass of airplane is much bigger than a bullet?
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1answer
54 views

Does precession of a rigid body change instantaneously?

I read some explanations of precession; this side for example summarizes briefly almost all what I have understood so far. But one thing bothers me: Following all this formulas, the precession ...
74
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6answers
9k views

Could we send a man safely to the Moon in a rocket without knowledge of general relativity?

I'm wondering if it's possible to send a man to the Moon using equations consistent with Newtonian gravity and without the elaborate tools of Einstein gravity. Are the predictions made by Newtonian ...
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2answers
55 views

How this formula for work follows from the definition?

If a particle moves along a path $\gamma : I\subset \mathbb{R}\to \mathbb{R}^3$ then the work done by a force $\mathbf{F}$ is defined by $$W = \int_{\gamma} \mathbf{F} = ...
2
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1answer
34 views

Does the line integral definition of Work involve distance or displacement?

My textbook reports the following definition of Work: where ds is the infinitesimal displacement. I know that an infinitesimal displacement is usually denoted by dr and I also know that the ...
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2answers
17 views

Elastic behaviour of objects

If I strike my car with a wrench with enough force to make a dent in it, then it's obvious that I won't be able to produce any acceleration in the car. But I am applying an external deforming force. ...
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4answers
188 views

What was the amount of energy released in the 9/11 terrorist attacks?

I read somewhere on the internet that the amount of energy released by the terrorist attacks on the twin towers on 9/11 should have been of the order of 100 tons of TNT. This number surprised me, ...
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1answer
47 views

Is there a difference between normal forces and centripetal forces?

Is there a difference between normal forces and centripetal forces? Or they just mean the same thing? My textbook talks about centripetal forces, but not about normal ones.
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0answers
48 views

Classical Mechanics Help [duplicate]

I'm an undergraduate student majoring in physics. I don't know why but classical mechanics is giving me a lot of problems and I can't seem to grasp the concepts at all. So far we've been doing ...
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2answers
44 views

Why doesn't $x$ reach a constant for a block experiencing $v^n$ resistive force? [closed]

I am stuck on the Exercise 3.5 of Newtonian Dynamics by R. Fitzpatrick: A block of mass $m$ slides along a horizontal surface which is lubricated with heavy oil such that the block suffers a ...
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3answers
86 views

Finding the angular velocity of a rod hit at a distance from its pivot [closed]

A 1m long, 2kg stick is nailed to the wall with a single nail, allowing it to pivot and freely rotate at the end. A 1kg ball, with speed 3m/s makes contact with the stick at some distance x (unknown) ...
0
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2answers
72 views

If an object rests on a table, not accelerating, how much work do both the object and the table do?

Obviously, the net work done is zero, because there's no motion, but is the proper way to look at it that both the object's gravity and the table's normal force do zero work, or that one does positive ...
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0answers
43 views

How to make sure projectile does not go through a wall?

I'm struggling with a problem, in which I want to determine initial condition (initial velocity, and angle) given that I know my ball has to reach (final velocity, location), but I want to make sure ...
1
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3answers
105 views

Does circular motion cause centripetal force OR does centripetal force cause circular motion?

Does circular motion cause centripetal force, or does centripetal force cause circular motion, or are they both occurring hand in hand together instantaneously? One more question: If I project a body ...
5
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2answers
158 views

Breaking the Laws of Physics? (Walter Lewin rotation experiment)

Lately i have been watching the MIT Physics Lectures from Dr. Walter Lewin. I find his passion while teaching very fascinating and inspiring. Any way, in the end of the lecture about Torque he showed ...
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1answer
37 views

Spring pulled with one end fixed [closed]

As the title says, if one end of a spring of mass $m$ is fixed to say, a wall, and the other one is pulled at a constant velocity $v$ by some external agent, we have to find the kinetic energy of the ...
2
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1answer
25 views

Wave hitting a boundary with a mass on it?

If we have a transverse wave that is infinite in the $-x$ direction and terminate by a mass $m$, that is allowed to move in the $y$ direction at $x=0$ as shown in the diagram below: I think we can ...
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2answers
72 views

Question about circular motion of car turning

When we move round a roundabout there is a frictional force between the tires and the road that acts towards the centre of the roundabout in order to produce the circular motion. Why then do we ...
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1answer
76 views

If I bend a rod, will its moment of inertia change?

In the first picture, there is a homogeneous metal rod of length $2L$ and mass $M$. If it rotates around a normal axis passing by $O$ (which is the center of gravity), then its moment of inertia is: ...
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2answers
63 views

How to determinate the minimum period of oscillation for a physical pendulum? [closed]

A physical pendulum consists of a thin homogeneous rod of length $l$, suspended by a point $O$ at a distance $x$ from the center of gravity ($x<\frac{l}{2}$), oscillating in a vertical plane. ...
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2answers
53 views

Can $F=ma$ be used to calculate ground reaction force of someone walking/running?

Can Newton's second law of motion $F=ma$ be used to calculate ground reaction force of someone walking/running?
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3answers
67 views

Why does weight affect acceleration with gravity

I'm sure this question has been asked before, but my question is different, because it can't be answered with some formulae. My question is, why do heavier objects decelerate faster when moving away ...
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1answer
80 views

Falling rope problem (disagreement with solution found at Problem Set)

On a frictionless table there is a homogeneous rope of length $L$ and mass. We push the rope such that it immediately starts falling due to gravity. Find the velocity when the rope has fallen of ...
3
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5answers
251 views

How is Angular Momentum Conserved when Mass is Released?

I am not a physicist (math/comp-sci) but I understand that Angular Momentum is supposed to be conserved. I find this confusing because there seems to be many simple, common cases where a restrained, ...
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3answers
51 views

Will water in an oil-filled jar sink or float?

If I pour a spoon of oil on a jar full of water no doubt it will float. But if I were to pour a spoon of water on a jar full of oil would it sink? Why or why not?
2
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0answers
53 views

Motion of a charged particle in a “solid” charged sphere (accounting for radiation)

Consider a particle (point charge) with charge $q$ and mass $m$ that crosses into a uniformly charged sphere (with charge $Q$ and radius $R$). The trajectory of the particle is a diameter of the ...
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1answer
34 views

How to find the centre of mass of 3 masses (astronauts and a rock) connected by a rope

To be more specific on the problem, a 50kg astronaut, an 80kg astronaut and a 20kg rock are tied together by a light rope during a space walk. I am asked to find the center of mass. Now, I've chosen ...
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3answers
117 views

Forces on a ball thrown upwards

When a ball is thrown up in upward direction, it is said that force is in downward direction. Why we don't we consider the force given to the ball to throw up in the upward direction? Is there is no ...
4
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2answers
136 views

Can net torque $\sum_i\mathbf r_i\times\mathbf F_i$ be expessed as $\mathbf r\times$ (net force) for some $\mathbf r$?

Let $\mathbf F_i$ be forces each of which is applied on $\mathbf r_i$ of a rigid body. Then is there a position vector $\mathbf r$ that satisfies $$\displaystyle\sum_i\mathbf r_i\times\mathbf ...
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1answer
35 views

What is quantum states of a gas? Is it the principle quantum no.?

When we write that the possible quantum states of a system are $S=1,2,3.\dots$, how is that related with the four quantum numbers, especially with the spin of a particle? Also according to BE ...
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1answer
45 views

How to turn this into a straight line

Right now, I am trying to turn my graph (which looks like a exponential graph) into a straight line graph, which starts at the origin (0,0). How would I do this? My values are given in the attachment, ...
0
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1answer
40 views

Decreased velocity away from gravity

Say I have a particle ($G$), which has the mass of the earth (hypothetically), and I have a second particle ($P$) moving away from $G$, in a line that is not parallel to the earth. Would this line ...
1
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0answers
48 views

Period of Paper Motion

A threatening note written on 8.5x11 inch paper is pinned to the door of a physics professor. The perpetrator left in a hurry so that when the physics professor finds the paper it is still swinging. ...
1
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1answer
52 views

Angular momentum in planetary disk formation

This question is actually more linked to astronomy and astrophysics than to pure physics. I tried posting it on the astronomy page, however it got no answers, so I though this page might help. ...
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1answer
45 views

Free fall of mass-spring-mass system

I am a little bit confused about the implication from my computation. Must have done something wrong in the computation. Assume we hold the top end of the mass-spring-mass system in the air, and the ...
0
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1answer
47 views

Should there be a linear force acting aside from torque?

Assume to identical motors are placed vertically on-top of a table and they are not fixed able to move/fall etc...and they have gears attached to them and are attached to one another like this image: ...
5
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2answers
371 views

Does the $\frac12mv^2$ law apply to quantum mechanics?

Consider the classical Hamiltonian for a spring: \begin{equation} H = \frac{1}{2}\frac{p^2}{m} + \frac{1}{2}kx^2 \end{equation} This is one of those simple cases where when you work out the math we ...
0
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1answer
109 views

If we dropped an object into the Pacific Ocean, would it completely sink to the bottom of the ocean floor or not?

Obviously if the density of the object is smaller than the density of water it would not sink at all. But I was thinking that, even if the density of the object is greater than the density of water, ...
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1answer
59 views

Projectile, air resistance and wind

So for my school project I am working on a projectile simulator and air resistance. So I have looked at this. Equations for an object moving linearly but with air resistance taken into account? ...
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0answers
24 views

Reaction Force on Garden Hose

In the lecture: Newton's First, Second and Third laws, (@ 20:34) whilst discussing Newton's third law of motion, Walter Lewin states that a garden hose snakes across his lawn when he turns the tap on ...
3
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1answer
83 views

Importance of the Galilean principle of relativity

The Galilean principle of relativity states that: The laws of mechanics are invariant in all inertial reference frames That means that if we have two inertial frames of reference $S$ and $S'$ ...
18
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4answers
2k views

Distinguishing between solid spheres and hollow spheres (equal mass)

If there are two spheres (hollow and solid) with equal mass and radius and we want to find the hollow sphere without using any equipment. What's the best way(s) to recognize the hollow sphere and ...
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0answers
20 views

Why does the Moon not rotate about its axis, relative to Earth's rotation [duplicate]

One of the common features of the Moon is the fact that only one face of the Moon is ever visible from Earth, regardless of how much of its orbit the moon has made about the Earth. This would imply ...
0
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1answer
45 views

The stronger the gravity, the faster an object will fall? [closed]

On a planet with gravitation ten times stronger than that of Earth's, will an object fall faster? Let's suppose that there are two planets; Roddo and Earth, respectively. Roddo has ten times the ...
0
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1answer
35 views

Equations of motion for a rocket

I'm trying to figure out how Tsiolkovsky rocket equation is derived. I've tried following along in the Wikipedia page and from my book, but I'm not getting it. First, are they assuming the ...