# Tag Info

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but perhaps, given sufficient throwing speed If you throw your egg too fast, the force due air resistance $$F = \frac{cW\cdot A\cdot \rho\cdot v^2}{2}$$ will exceed the 50 Newton you mentioned before and the egg will break. and, or, car speed, perhaps it is possible If the car speed is fast enough the glass will of course break, since even ...

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Even classically, forces arise from field being propagated at the speed of light. A physically relevant object is the energy-stress tensor, whose components represent energy density and momentum current density, so indeed momentum can be interpreted as a current that is conserved over time (as a consequence of symmetries). This point of view is also ...

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Noether theorem tells you that if you can find a (one parameter) group of infinitesimal transformations $\alpha$ and $\beta$ such that: $$t'=t+\alpha\epsilon$$ $$q'^\mu=q^\mu+\beta^\mu\epsilon$$ and your lagrangian is invariant under this group of transformations, then the quantity ...

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So this is a bit tricky actually and perhaps the original question makes this more clear. The problem I'm having when thinking about this is what exactly does the function generator do. Does it take the original force of the string and add some force $F(t)$ on top of it, or does it essentially fix the force on one side of the spring? So if the spring is ...

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Think of the function generator producing prescribed displacements $X(t)$. What is the extension of the first spring? It is $x$, so its restoring force is $-k_1 x$. Now what is the extension of the second spring? It is $X(t)-x$, with its restoring force $-k_2 (X(t)-x)$. What is missing from the diagram is the direction of positive forces and displacements. ...

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The power input is roughly constant (that of a car is dictated by the total engine power while for a bicycle it depends on the user). The gear or similar tools adjusts the mechanical advantage so that a low gear will express the engine power in force rather than speed (recall that power is force times speed). On higher gears the force is traded in for speed. ...

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Nothing is incompressible, but most liquids and solids have a very low compressibility i.e. a very high bulk modulus. The reason for this is that in liquids and solids the atoms/molecules are in contact with each other. To squeeze them closer together you need to deform the bonds in molecules and/or the electron distribution around atoms. Both processes ...

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Work= force x displacement force is weight and displacement is 0 so there is no work (in physics)

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By definition, work is $$W[\gamma] = \int_\gamma\mathbf F\cdot\mathbf v\text dt$$ i.e. force times displacement. If an object is not moving, even if subjected to a force, then there is no work done by said force. Observe that, since the object is not moving, the sum of all the forces applied to a body must be zero. For example, a body on rest on a table is ...

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Well I was still confused after reading these answers so I found a book "Cosmology and astrophysics through problems" by T Padmanabhan that finally answered the question in a (fairly) clear way. Basically for a system with n degrees of freedom, you have $n$ Euler-Lagrange (E-L) equations. Since these equations are second order partial differential ...

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