- #1
greypilgrim
- 506
- 36
Hi.
Usually the law of the lever or similar force laws for simple machines are derived using
$$W_1=F_1\cdot s_1=F_2\cdot s_2=W_2\enspace,$$
sometimes called "Golden Rule of Mechanics". However, these force laws also hold in the static case where no work is done. Is it possible to derive the law of the lever without using any displacements, not even infinitesimal or virtual ones? As far as I can see, such a derivation would have to be independent of conservation of energy, as mechanical work is defined in terms of displacements.
Usually the law of the lever or similar force laws for simple machines are derived using
$$W_1=F_1\cdot s_1=F_2\cdot s_2=W_2\enspace,$$
sometimes called "Golden Rule of Mechanics". However, these force laws also hold in the static case where no work is done. Is it possible to derive the law of the lever without using any displacements, not even infinitesimal or virtual ones? As far as I can see, such a derivation would have to be independent of conservation of energy, as mechanical work is defined in terms of displacements.