The drawing shows an equilateral triangle, each side of which has a length of 2.00 cm. point charges are fixed to each corner, as shown. the 4.00 microc charge experiences a net force due to the charges qa and q b. this net force points vertically downward and has a magnitude of 405 n. determine the magnitudes and algebraic signs of the charges qa and q b.

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.