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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how much force is necessary to move a 3368# airplane?

I have an airplane on tricycle gear (nosewheel and 2 main wheels under the wing). Sometimes I need to move it back and forth in the parking area. How much force must I apply to move it? The reason ...
0
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1answer
18 views

Period of swinging incomplete hula-hoop

I was working on a problem where I had to calculate the period of a swinging incomplete hula-hoop given its center of mass and radius. It only swings with very small amplitude so I considered the ...
2
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2answers
39 views

Does constant velocity of center of mass imply linear momentum is conserved?

I know that if momentum is conserved for a system, you can derive that the velocity of the center of mass of that system is constant. I was wondering if the second condition also implies the first: if ...
6
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2answers
130 views

Mass particle trajectory on a sphere

So, I am trying to simulate mass particle motion on the outer surface of sphere using cartesian coordinates. Let's conclude just a gravity and frictionless movement. Sphere $x^2 + y^2 + z^2 = 1$, ...
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4answers
3k views

What's the difference between centre of mass & centre of gravity for massive bodies?

My book says: For most of the small objects, both are same. But for mammoth ones, they are really different ones. And in a gravity-less environment, COG is absent; COM still exists. Ok, what's ...
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0answers
8 views

Is solving Verlet constraints parallelizable? [migrated]

I am a computer science student and I came across the Verlet Cloth simulation. An implementation is here. I was interested in how such computation would lend itself to parallelization. The problem ...
3
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0answers
54 views

Trying to modify the Tsiolkovsky rocket equation for the real world

Everyone knows about the famous Tsiolkovsky rocket equation. However, he formulated the equation neglecting many things. So, here, I am trying to find the real equation. My thinkings: Suppose, the ...
5
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7answers
3k views

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 ...
3
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1answer
31 views

Frictional force require to balance leaning sticks

Here is the question (from Morin's Introduction to Classical Mechanics book): One stick leans on another as shown in Fig. 2.21. A right angle is formed where they meet, and the right stick makes ...
0
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1answer
31 views

Minimizing a damping constant in order to minimize the amplitude of oscillations

How can I determine the damping coefficient that minimizes the amplitude of vibrations? This is an extension of Coupled ODEs that model a quad rotor \begin{align} ...
2
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3answers
68 views

Intuition and difference between centrifugal force & Coriolis force?

My book says that when a frame rotates uniformly, pseudo/fictitious force must be taken to count. This is centrifugal force. Also, while Googling, I found another pseudo force Coriolis force. ...
0
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1answer
132 views

Understanding of the $m v^2/2$ formula for kinetic energy

I have some problem to intuitively understand why the kinetic energy grows quadratically with the velocity (at least in non-relativistic case). Assume the following experiment: we launch an unmanned ...
0
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3answers
47 views

Finding minimum force to hold a particle in equilibrium [closed]

A particle of mass $m$ is suspended from a point A on a vertical wall by means of a light inextensible string of length $b$. Find the magnitude and direction of the minumum force $\boldsymbol P$ ...
1
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2answers
43 views

Flipping a bottle

I tried to do this experiment recently at school and my house. I started the experiment by having three same type of bottles with the labels A,B and C. Bottle A has been fully filled with water, ...
3
votes
1answer
71 views

Limits of A Mechanical Processor [closed]

Is it possible to build an electromechanical processor at high speed and capacity, with the same functionality as of today's modern microprocessors consisting of millions of transistors? I mean, ...
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2answers
77 views

Why do these two derivations of the formula for impulse contradict?

I was trying to derive $I = F\Delta T$ from $p = mv$. First I converted $v = at$: $$\begin{align} p &= mv \\ p &= m \times at \\ p &= ma \times t \\ p &= Ft \\ \Delta p &= F ...
0
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1answer
22 views

Torque on shaft

Consider a generator which supply power using a shaft to a turbine. The torque applied on shaft by generator is $T$. As the shaft has constant angular velocity the turbine should also be applying ...
0
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2answers
47 views

How to check if a system is in SHM in two spring systems?

I must determine if the system (a) is in SHM. I must arrive to the conclusion that there is a linear restoring force such that $a=-w^2x$. The solution's manual affirms that according to Newton's ...
0
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4answers
156 views

Why is $M\frac{dv}{dt} = v_{rel} .\frac{dm}{dt}$ correct and $(M - dm)\frac{dv}{dt} = v_{rel} .\frac{dm}{dt}$ wrong?

Newton's 2nd law of motion can't be applied for mass-varying systems. Another force, known as Thrust must come to play. It can be measured using law of conservation of linear momentum. ...
0
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1answer
37 views

How do I incorporate friction and mass when analyzing spring motion?

Problem 12 of section B of this PDF file reads Two springs with spring constant k1 and k2 are attached to a body of mass (m) in two different configurations in 2 cases (A and B) as shown. ...
0
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1answer
34 views

Problem on coefficients of friction? [closed]

How to approach problems where both coefficients of static and kinetic friction are given? Like in this: A 42 kg slab rests on a friction-less floor. A 9.7 kg block rests on top of the slab, ...
0
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2answers
32 views

Why isn't there a net force when two rods touch each other?

This is a problem from Beer and Johnston's Mechanics of Materials (Amazon link). There's a problem in which there are two rods of different material, area, and length. The rods are fixed to walls, ...
0
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2answers
29 views

Prevent a box from tipping over: height of CG?

I'm on a problem that can be simplified in the following way: A box is placed on a horizontal plane, and is pinned to the ground on one side only such that it can tip over that side. Given a ...
3
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1answer
82 views

Waves and Newton's Third Law

I'm a really newbie in Physics trying to understand a bit about waves. Firstly, i'm using the Wikipedia's definition of wave , that is, as energy traveling through a medium/space without ...
2
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2answers
43 views

The principles of statics without force

I'm a student of civil engineering and now my course is covering the basics of statics, such as the equations of equilibrium, etc. Trying to get a better basis on the subject, I started to search on ...
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1answer
29 views

Newtonian Mechanics Cart Problem (Formula Derivation) [closed]

So I have a problem that reads: You exert a force of a known magnitude F on a grocery cart of total mass m. The force you exert on the cart points at an angle θ below the horizontal. If the cart ...
8
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7answers
578 views

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. ...
0
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1answer
28 views

Finding the moment of inertia of a lever [duplicate]

I am required to find the moment of inertia of the lever for a project in physics. This is my attempt: Please note that we have not been taught this yet in class so i have not been taught this ...
0
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2answers
54 views

Is this a correct understanding of circular motion?

We say an object experienced uniform circular motion iff it moves in a circle of constant radius, with constant angular velocity. To experience uniform circular motion, must the net force on the ...
3
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2answers
91 views

Introducing angular momentum for the first time to a class

What is the best way to introduce the notion of angular momentum to a class without making it appear an unnecessary and artificial construction?
0
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1answer
25 views

Enstrophy and energy spectral density of vorticity

I'm processing some flow field data obtained by PIV for a turbulent jet with the intention of using the energy spectral density (ESD) function to say something about the processes going on. I'm ...
1
vote
1answer
28 views

Why, in a car taking a sloped curve, friction is perpendicular to the car

In solving the problem we usuallly use the friction as the centripetal force, but I could never understood how is this possible. I understand that if a car is making a circular motion, some ...
4
votes
4answers
215 views

Why does a spring fixed to a wall have PE and not KE?

As many books,including mine (Principles of Physics by Resnick and Halliday) introduce, I also will present my example like this: Let there be a spring of negligible mass attached on one side ...
10
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2answers
1k views

Calculating the force required to lift a weight with a screw

I am trying to learn physics by myself as I do not have a good teacher at school. I've been reading Feynman Lectures on Physics and I can't figure out how he found out this number. Here is an excerpt ...
0
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0answers
17 views

Pulling fabric in a saddle shape tight with a spring

Jokingly a friend and I thought of a way to suspend a tarp-like material over my porch, very similar to they way a trampoline is sprung. However, this fabric is a rectangle and fits over arches. My ...
-1
votes
1answer
29 views

How do you measure the acceleration of two objects with different masses? [closed]

I would like to know how to measure the acceleration of two objects with different masses...(and the formula that's used.) For instance a steel ball that, say...weighs 67g and a wooden ball that ...
0
votes
1answer
29 views

Standing Waves. Two questions. Please help! [duplicate]

Every time I read an article/text about standing waves they seem to specifically mention that whenever a wave pulse hits a hard boundary it gets reflected back with it's phase changed through 180 ...
0
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2answers
35 views

Finding the Work done

Find the work done for an object to slide down an inclined plane against the frictional force. The answer my book shows is : $$ W = mg ({\mu}_k \cos \theta - \sin \theta) S $$ where S = displacement ...
-1
votes
1answer
48 views

2012 quo. no. 14 $F_{net} = ma$ [closed]

Please refer to #14 in this document Please help me solve this problem... I don't understand why a force (in the problem, T) even needs to be applied to keep the ball in equilibrium. There is no ...
-1
votes
1answer
44 views

A Special Case About Projectile Motion [closed]

There is a common fact about projectile motion. Let me remind you with an example: Assume that you are aiming at a hanging banana on a tree. If there were no gravitational force, the bullet would ...
2
votes
2answers
76 views

Recoil from a photon gun

Suppose you have a laser gun or a gun that shoots high frequency photons. Now according to Newton's laws there should be an equal and opposite reaction. So the question is - Will there be a recoil ...
0
votes
1answer
111 views

What is this simple mechanism called? [closed]

I often build with Lego and use this mechanism: It converts the rotational movement to linear by making the stick between the two blocks go back and forth. What is this mechanism called?
1
vote
0answers
58 views

Throwing a baseball against the back of a car [closed]

We, some fellow students and I, are trying to figure out what to. But we simply do not know which formula to use at question a. We found the following: $\Delta P=(2mv_{ball,i}M)/(m+M)$ Could someone ...
2
votes
2answers
32 views

What are the forces acting on a Pendulum Tuned Mass Damper?

Upon researching tuned mass dampers, I came across this free body diagram of a pendulum tuned mass damper. However, I don't understand where many of the forces come from. What exactly are the forces ...
0
votes
2answers
66 views

Mathematical subtlety in a physics problem

A wagon of initial mass $M$ is moving with an initial velocity $V_o$. Now sand starts accumulating on this wagon, increasing the total mass from $M$ to $M+s$. We have to find the final velocity of ...
2
votes
1answer
76 views

Disk and Ball on a smooth surface [closed]

A uniform disk of mass $\text{2m}$ and radius $\text{R}$ is placed freely on a smooth surface as shown in the figure. A particle of mass $\text{m}$ is connected to the circumference of the disc with a ...
0
votes
1answer
22 views

Problem on Inclined Forces [closed]

I am having trouble on one of my homework problems. The problem is What is the acceleration of the system if M1 is 5 kg and M2 is 4kg and the coefficient of friction between M1 and the table ...
0
votes
2answers
48 views

Can the relative position of two masses connected by a spring become negative?

Consider the following diagram. Two masses of 1 kilogram each are attached by a spring of 1 N/m. The $x$-axis is chosen such that $x_1(0)=0$ and $x_2(0)=L$ where $L$ is the length of the spring in ...
0
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1answer
28 views

Is the movement of a projectile in 2D a Holonomic system? [closed]

Is the well known problem of the movement of a projectile, no friction, in two dimensions a holonomic system? If yes.. Why? If Not.. Why?
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2answers
47 views

What is the zero of potential?

A satellite of mass $m$ is travelling at a speed $v_0$ in a circular orbit of radius $r_0$ around a fixed mass at $O$. Taking the zero of potential at $r=\infty$, show that the total energy of the ...