How do you find the elastic constant on a force extension graph?

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?

What is the difference between mass density and weight density?

Abeam of light shining from water to air strikes the surface at an angle greater than 48 degrees and produces total internal reflection. if the incident beam is at a 50 degree angle what angle is the reflected beam 13 25 50 100