Un cañón de electrones dispara electrones (q = -e, me = 9.1 × 10 -31 kg) hacia una placa metálica que está a 4.0 mm de distancia en el vacío. El potencial de la placa es de 5.0 V menor que el del cañón. ¿Cuán rápido se deben mover los electrones al salir del cañón si deben llegar a la placa?

Total solidification times of three casting geometries are to be compared: a sphere, a cylinder, in which the length-to-diameter ration - 1.0, and a cube. volume = 1000 cm^3 for all three shhapes, and the same casting alloy is used. a) determine the solidification times of each geometry b) based on the results of part (a), which geometric element would make the best riser? c) if the mold constant = 3.5 min/cm^2 in chvorinov's rule, compute the total solidification time for each casting.