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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2answers
70 views

Does Buoyant Force always act upwards?

I have always used buoyant force as acting upwards in any problem related to fluid mechanics that I have solved. Also, if we push a mug down a bucket of water. It rises up, always, not diagonally even ...
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1answer
42 views

Calculate the magnitude of the acceleration due to gravity including its uncertainty?

I made a free fall time experiment and now I'm trying to make a report. The experiment consists of releasing a steel ball from various heights hi and measuring corresponding free fall times τi . ...
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2answers
76 views

Use equations to create a realistic problem [closed]

Given the following equations: $100$ m = $0$ m + ($50 \cos\theta$ m/s)$t_1$ $0$ m = $0$ m + ($50 \sin\theta$ m/s)$t_1$ - $\frac{1}{2}(9.80$ m/s2$) t_1^2$ I am supposed to make up/create a real-life ...
3
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2answers
73 views

Throwing masses to gain velocity. A question of efficiency

I was thinking the other day of a system in which you eject mass. And then I wonder whether it was more efficient to throw a big mass or many little. Let me put it in other terms. Suppose you are ...
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1answer
26 views

slip definition that works in game

Wikipedia article gives us the following 2 equations: $\%_{slip} = \frac{\omega r - v}{|v|} * 100$ (The use of $v$ modulus makes it work in all directions. It is multiplied by 100 to get the ...
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0answers
11 views

Computing the dynamics with a bilateral constraint in position

Let's says I have a dynamical system of generalized coordinates $x$, subject to a bilateral constraint $g(x(t),t)=x_1(t)-d(t)=0$ where $d$ is a prescribed displacement. I am looking for the ...
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1answer
57 views

Equation of Motion for spring-cylinder-mass system [closed]

Hello, I hope someone can help me with this question, to find the equation of motion of the disc for small angular rotations. The mechanism comprises of a uniform circular disc of mass $m$, spring ...
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0answers
17 views

How is the centrifugal force responsible for Earth's oblateness? [duplicate]

I'm having serious problems understanding the centrifugal force caused by Earth's rotation. How does it affect the Earth's shape? Should I draw the gravitational acceleration (the one in Newton's ...
0
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0answers
24 views

Do EM waves create action in receiver antenna without reaction?

If EM waves such as radio waves, can induce electrons in the receiver antenna to move, and electrons have a small amount of mass, isn't this action without a reaction? Is it possible to use the ...
0
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1answer
31 views

Pure rolling between two moving sufaces

I know about pure rolling on one surface, where the ICR (instantaneous center of rotation) is the point of contact with the ground. But what if the the body is forced to roll between two surfaces ...
0
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3answers
78 views

Gravitational acceleration of asteroids [closed]

If an asteroid is moving through space at a speed that exceeds escape velocity of the earth and that asteroid is on a collision course with the earth will the asteroid Accelerate as it falls into the ...
0
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3answers
37 views

Finding an object's final velocity with distance dependant force [duplicate]

I am (just for fun) trying to calculate the velocity with which the moon would impact the earth if it stopped orbiting and simply headed towards earth. I know the force is $\frac{G m_1 m_2}{r^2}$. ...
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0answers
25 views

How will you calculate the pressure inside a planet of fluid at a distance r from centre?

How will you calculate the pressure inside a planet of fluid at a distance r from centre? I tried using concept of solid angle and even potential energy but was unable to get answer.
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1answer
63 views

Why does centripetal acceleration equals $v^2/r$?

I have found something on wikipedia, but I don't understand why does the $v(t) \frac{\mathrm du_t}{\mathrm dt}$ equals with $\frac{v^2}{r} u_n$.
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1answer
72 views

Need motion equations for falling ball for simulating [closed]

I am currently M.S student in artificial intelligence(A.I) and working on my thesis on reinforcement learning, which robot should learn by itself how to control a quadcopter. Long story short, I have ...
0
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0answers
16 views

Spring constant of a union of springs - Why is it so? [duplicate]

As I was learning about springs, I bumped into a theory saying that if we take one, long spring and divide it (cut) into, let's say, two springs of the same length, their spring constant will be $k = ...
4
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1answer
48 views

Breaking strength of wet paper/cloth

In the Hollywood movie, Shanghai Knights (pardon me for the non scientific citation), Jackie Chan states that 'wet cloth' does not break easily. How true a fact is this ? We know from common ...
3
votes
3answers
560 views

Spring pendulum - why is it possible to use this equation?

It is known that, when we describe the spring pendulum, we are bound to use the formula $T = 2\pi \sqrt{m/k}$, however, we can go further and set $\omega = \frac{2\pi}{T}$ I ponder why is this ...
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2answers
153 views

what is actually mean by momentum in deepest level of physics?

What does something called "Momentum" actually measure?I know that generally momentum of a object is describe by the multiplication of mass and object's velocity and it is a conserve quantity without ...
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2answers
31 views

Projectile motion dependency [closed]

I have read that in projectile motion both vertical and horizontal components are independent of each other but i don't get it that how it is possible i think that they are dependent. If they are not ...
3
votes
1answer
61 views

Will centre of gravity coincide with centre of mass if density of object is non uniform?

I read that for bodies of very large dimensions, but having non-uniform density, the centre of gravity does not coincide with centre of mass. I can understand that with large dimensions the strength ...
-3
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0answers
49 views

How high does an arrow fly, when shot straight up in the air?

How high will an arrow fly, when shot straight up in the air ? There is already a similar question, but it neglects the air resistance I would like to know how significant is the air resistance. Is ...
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1answer
44 views

Distance of closest approach of a satellite after star explodes [closed]

Problem: A satellite is in a circular orbit about a star, when it explodes spherically symmetrically, to a large distance from the star and in negligible time. The star loses 2% of its mass. I want ...
16
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8answers
4k views

Why doesn't orbital body keep going faster and faster? [duplicate]

If we consider the change in velocity during an infinitesimal interval of an orbit: where body B is orbiting body A, we can see that the magnitude of the resultant vector (the green arrow) is ...
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1answer
49 views

How do you determine which way two objects will travel after collision when given their respective masses and speeds?

I was practicing some Mechanics, and I came across a problem that involved an impact between two objects: I understand how to approach the question: Apply the conservation of momentum, and use the ...
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2answers
25 views

Finding Amplitudes of Resultant Mechanical Waves

Let's say I have two arbitrary mechanical waves $y_1$ and $y_2$ propagating on a string in the same direction. The waves $y_1$ and $y_2$ differ in phase by an arbitrary angle $\phi$ and the ...
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1answer
17 views

Power needed to raise a bucket at a constant speed by a pulley

This is the last section of this pulley exercise: The bucket in is filled with water so its total mass is now $45$ kg. The bucket is raised at a constant speed of $2.0$ $ms^{-1}$ using an ...
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2answers
28 views

If a block moves on a straight line (no friction) for time $T$ and then along an incline plane, what will the displacement vs. time graph look like?

In my opinion, the graph for the first part of the motion will be a straight line passing thorugh the origin (at the beiginning of motion) and then it will be a falling parabolic curve ( $x$ is ...
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0answers
40 views

Natural Frequency and Inertia Tensors

The natural frequency of an oscillating object attached to a torsional spring is obtained by $\omega _n=\sqrt{\frac{k}{I}}$ In the case of single DOF motion, the moment of inertia is simple. ...
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1answer
31 views

Confused about shear elasticity and complementary shear stress

I am a self learner of continuum mechanic. I am confused about simple shear stress in situation similar to figure 1, in case $F_\textrm{ext}$ is caused by external perturbation by i.e., human, what ...
1
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1answer
63 views

Normal reaction [closed]

Consider a plank on a frictionless surface and a ball from a height H is dropped on this plank. There is no friction between the plank and ball. Can the plank jump up in air for any value of H? I ...
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3answers
49 views

Change in linear momentum [closed]

Let A and B be to rigid blocks. A is stationary while B is moving with a velocity $u$. So if B collides with A. (These blocks are on a frictionless surface.) What would happen after B collides with ...
3
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2answers
66 views

Pulley rotation

In the given arrangement, the friction in between the string and the pulley is enough to avoid slipping and the string is light. On the basis of these assumptions, would the tension in the upper ...
7
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2answers
702 views

Conservation of momentum when one body is fixed

When we fire a gun, it recoils. Both bullet and gun gain in momentum. Before the shot, momentum of both is zero. If we make the gun unmovable somehow, after the shot, what will be the effect on the ...
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2answers
39 views

Simple question about inclined planes

Assuming all surfaces to be frictionless. If the mass of the inclined plane is large enough, could $N$ ever be equal to $mgcos\theta$. Reasons? So far I've come up with: $mgcos\theta - N = ma$ ...
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0answers
34 views

Inconsistent Mass matrix in Euler Lagrange dynamics

I am trying to derive Euler Lagrange dynamics of a two body system that is translating and rotating in a plain. First body is given by $(x,z,\theta)$ where $(x,z)$ is position of the center of first ...
1
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3answers
91 views

When a bomb explodes, does it momentum remain same?

If, from an aircraft, a bomb is thrown to an object placed at ground and bomb explodes before it hits the object, i.e if it explodes in the middle of its path, does it momentum remain same? I knew ...
4
votes
4answers
108 views

Two mass one-spring system natural frequency

Suppose I have two masses $m_1, \ m_2$ connected by one spring of stiffness $k$ through their centres of mass, lying on a frictionless surface and the system is set into oscillation. I want to find ...
0
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4answers
104 views

Why don't two objects move with the same velocity after collision?

I have a problem with understanding the nature of collisions and their outcomes. From my understanding, I come to think that when a mass collides with another, both of them should always have equal ...
1
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1answer
34 views

Spinning top fixed point

I have seen many explanations about the movement of a spinning top. The explanations were in a varied level, from basic newtonian mechanics to Lagrangian formalism. But I do not understand why some ...
0
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0answers
29 views

How do things accelerate if every time they accelerate they get accelerated in the opposite direction? [duplicate]

Let's say that I have a book infront of me. I push it and it accelerates. According to Newton's third law I would have experienced the same force. But if I experience the same force in the opposite ...
0
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0answers
21 views

Contact Angle In Capillary

One Professor recently told me that in an insufficient length capillary, the contact angle doesn't change, its an inherent property which does not change. If the edges of capillary are extremely sharp ...
6
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3answers
2k views

Advantages of Lagrangian Mechanics over Newtonian Mechanics [closed]

Here, I'm going to pose a very serious list of doubts I have on Lagrangian Mechanics. Can we learn Lagrangian Mechanics without studying Newtonian Mechanics? Does Lagrangian help in solving problems ...
0
votes
1answer
147 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 ...
3
votes
2answers
57 views

Why are upthrust and normal reaction force not the same?

I am currently studying IGCSE Physics, and have the following question: Why aren't upthrust and normal reaction force not the same. I understand that upthrust only occurs in fluids, and normal ...
-5
votes
1answer
74 views

What is exact difference between gravitational force and magnetic force? [closed]

I've read that gravitational force is due to mass only and magnetic field is due to moving charged particles. But my question is: what are other difference between them? Can we set up a small ...
2
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1answer
60 views

Work done in bringing down a body [closed]

A block of mass $30$ kg is being brought down by a chain. If the block acquires a speed of 40.0 cm/s in dropping down $2.00$ m, find the work done by the chain during the process. I have calculated ...
0
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0answers
27 views

Keplerian orbits and radial velocities: problem with true anomalies

I am writing a pure Python code to calculate radial velocities of stars with massive objects orbiting them. I am following the formalism from Murray & Correia (2011) (hereafter MC11). In a given ...
1
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0answers
35 views

Newton's third law confusion [duplicate]

If A exerts a force of 200N on B, then by newton's third law, 200N would be exerted on it. Similarly, if B exerts 100N on A, by newton's third law, 100N would be exerted on it. Therefore the net ...
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votes
1answer
68 views

What does $P = Fv$ mean? [closed]

The engine of a car is developing a power of 90kW when it is moving on a horizontal road at a constant speed of 100 km h−1. Estimate the total horizontal force opposing the motion of the car. I ...