Which conclusions and inferences are best supported by the data? Check all that apply.

-Natural gas is the best type of energy.

-Nuclear electric power is the worst type of energy.

-Petroleum and coal account for more than half of the energy used in the United States.

-Natural gas and coal account for more than half of the energy used in the United States.

-Natural gas and nuclear electric power account for less than half of the energy used in the United States.

Resistivity of a material is the resistance of a cm long sample of the material of 1 cm2 cross-sectional area.

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.

When thorium (90 protons) ejects a beta particle, the resulting nucleus has question 18 options: 87 protons. 88 protons. 89 protons. 90 protons. none of the above