machine X is 3 times more powerful than machine Y which one of the e following is true A. machine x does 1/3 as much work as machine Y in the same amount of time B. machine Y does the same work as machine X in 1/3 the time C. machine X does the same amount of work in 1/3 the time it takes machine Y?

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.

Two resistors r1 and r2 may be connected either in series or parallel across an ideal battery with emf ε. we desire the rate of energy dissipation of the parallel combination to be 8.75 times that of the series combination. if r1 = 105 ω, what are the (a) smaller and (b) larger of the two values of r2 that result in that dissipation rate?

Scientific models are based on current knowledge, which can limit their effectiveness when new discoveries are made.