11 Masse volumique du polystyrène Le polystyrène est un matériau plastique
transparent dont on fait par exemple
certains gobelets. Si l'on y souffle
un gaz lors de sa fabrication, on
obtient du polystyrène expansé,
sous forme de boules blanches.
1. La boule de polystyrène expansé
de la photographie a un diamètre de
12 cm. Calculer son volume.
2. La masse de cette boule est de 14 g.
Calculer la masse volumique du polystyrène expansé.
3. Si l'on immerge totalement un gobelet en polystyrène
dans l'eau, il coule. Est-ce que, comme lui, cette boule
coulerait ? Justifier.

Bernie drove home from a vacation in 1.5 hours. he traveled a total distance of 60 miles. what was his average speed in miles per hour? a. 60 mph b. 90 mph c. 40 mph d. 55mph

Steam is generated in a boiler of a cogeneration plant at 10 mpa and 450°c at a steady rate of 5 kg/s. in normal operation, steam expands in a turbine to a pressure of 0.5 mpa and is then routed to the process heater, where it supplies the process heat. steam leaves the process heater as a saturated liquid and is pumped to the boiler pressure. in this mode, no steam passes through a condenser, which operates at 20 kpa. (a) determine the power produced in the turbine and the rate at which process heat is supplied in this mode. (b) determine the power produced in the turbine and the rate of process heat supplied if only 60 percent of the steam is routed to the process heater and the remainder is expanded to the condenser pressure. (3.32 mw; 9.69 mw; 4.25 mw; 5.82 mw)

Which boundary is associated with the building of the himalaya mountains? convergent transform divergent hot spot