wo children of mass 22 kg and 51 kg sit balanced on a seesaw with the pivot point located at the center of the seesaw. If the children are separated by a distance of 5 m, at what distance from the pivot point is the small child sitting in order to maintain the balance

The center of a long frictionless rod is pivoted at the origin, and the rod is forced to rotate in a vertical plane with constant angular velocity \omega. write down the lagrangian for a bead of mass m threaded on the rod, using r as your generalized coordinate, where r, \phi are the polar coordinates of the bead. (notice that \phi is not an independent variable since it is fixed by the rotation of the rod tobe \phi = \omega * t) solve lagrange's equation for r(t). what happens if the bead is initially at rest at the origin? if it is released from any point ro > 0, show that r(t) eventually grows exponentially. explain your results in terms of the centrifugal force m* \omega ^2 *r.

1. do the particles in the medium material move in the same direction of the wave or at opposite direction to the wave? explain your answer. 2. by inputting more energy into the wave, i.e a large shake of the spring, which wave property also increases? 3. are there forces of friction acting while a wave is passing through a medium?

Why does lightning travel from clouds to the ground? a. the negatively charged ground attracts the positive charge from the clouds b. charges are exchanged between negatively charged clouds and positively charged ground c. gravity pulls the negatively charged energy from clouds downward d. gravity pulls the positively charged energy from clouds downward