A 0.4kg ball is thrown straight up into the air and reaches a maximum altitude of 20m. Taking its initia position as the point of zero potentia energy and using energy methods, find (a) its initia] speed, (b) its total mechanical energy, and (c) the ratio of its kinetic energy to the potential energy when the ball is at an altitude of 10m.​

Copper has free electrons per cubic meter. a 71.0-cm length of 12-gauge copper wire that is 2.05 mm in diameter carries 4.85 a of current. (a) how much time does it take for an electron to travel the length of the wire? (b) repeat part (a) for 6-gauge copper wire (diameter 4.12 mm) of the same length that carries the same current. (c) generally speaking, how does changing the diameter of a wire that carries a given amount of current affect the drift velocity of the electrons in the wire?

The density of a liquid could be found by using

Which of the following is the result of the nuclear weak force? the instability of large nuclei the repelling force between positively charged protons the structure of the atom certain types of nuclear decay