The northern hemisphere is warmer in spring than in winter, because in spring

You have 80 g of 60oc water and 80 g or 10oc water. what is the final temperature when the two are mixed? explain.

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.

Hurry! how much heat is absorbed by a 72g iron skillet when its temperature rises from 11°c to 23°c?