# Tagged Questions

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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### Confusion in understanding Coriolis force example

I am learning Classical Mechanics from a book called Newtonian mechanics by AP. French. The book tries to explain Coriolis force with an experiment as an example which confounds me. The book goes ...
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### Illustrating the definition of Young's modulus from spring factor

The relationship between Young's modulus $E$ and the spring factor $k$ from Hooke's law is $k=\frac{E A}{L_0}$ where $L_0$ is the initial length of the stretched material and $A$ the cross-...
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### Four particles arranged in a square and rotated on a turntable [closed]

A question reads. Four particles, each of mass 3kg, are connected by light, inextensible strings, each 0.08m long, so that they form a square with the particles at the corners and the strings ...
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### Ball rolling down an incline and dynamics in general

I recently performed an experiment for a class which involved measuring the projectile motion of a ball after it had rolled down a ramp and exited on a significantly smaller ramp. When interpreting ...
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### Vertical circular motion/How can tension be negative?

This is a rock tied to a string spinning vertically. Here, $T+mgsin\theta = mv_1^2/r => T = mv_1^2/r-mgsin\theta$ Suppose I give it a velocity $v$ at the bottom. 1) At what angle $\theta$ will ...
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### Average acceleration: why I am getting different results?

Let's consider a simple school problem. A car starts moving during 3 seconds with a constant acceleration of 1 m/s^2. Then it stops accelerating and moves 3 seconds more with a constant speed. Find ...
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### Astronauts on a tether

Recently, I went to a competition with a science test. One of the questions was as follows: Two astronauts (A and B) are tethered together in space. Simultaneously, Astronaut A pulls on the tether ...
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### Equations of Motion of a Physical Pendulum [closed]

I would like to formulate the equations of motion of a particular type of physical pendulum, shown in the attached figure. The physical pendulum consists of a wheel rolling on a narrow board. A ...
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### Velocity Related To Gravitation [closed]

Which Equation is correct $v^2=\large{\frac{2GM}r}$ OR $v^2=\large{\frac{GM}r}$? I am getting confused here.
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### Does Newton's third law remain totally unchanged even in Einstein's theory?

Why Newton's third law remain unchanged still now in relativity theory (as for example that is why we feel weight due to equal but opposite reaction of the Earth's surface)?
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### Why did Trebuchet have so long throwing arms?

Have a look at such an historical Trebuchet: As you can see, the throwing arm (left) is much longer than the weight arm (right). Law of conservation of energy says, potential energy from the ...
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### How do we define what is “External” force or “Internal” force in the context of momentum conservation?

I know that without presence of any "External" force momentum is always conserved. But how do we distinguish between "External" force and "Internal" force where all are "Force"?
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### Are mechanical energy of an element of a rope and energy density constant in the case of mechanical waves?

I'm confused about energy driven by a wave. Consider a sinousoidal wave moving in a rope. In my view each element $dm$ of the rope follows a simple harmonic motion in time. That means that the ...
My attempt: $mgh = \frac{1}{2}I \omega^2$ $\omega^2 = 2 \alpha\Delta \theta$, so $mgh = \frac{1}{2}I 2 \alpha \Delta \theta$ $mgh = I \alpha \Delta \theta = \tau \Delta\theta$ \$\tau = rF\sin \...