At any angular speed, a certain uniform solid cylinder of diameter D has twice as much rotational kinetic energy as a certain uniform thin-walled hollow cylinder of the same diameter when both are spinning about an axis through their centers. If the mass of the hollow cylinder is m, the mass of the solid cylinder is
A) 1/4 m.
B) 1/2 m.
C) m.
D) 4 m.
E) 8 m.

Consider an ordinary, helium-filled party balloon with a volume of 2.2 ft3. the lifting force on the balloon due to the outside air is the net resultant of the pressure distribution exerted on the exterior surface of the balloon. using this fact, we can derive archimedes’ principle, namely that the upward force on the balloon is equal to the weight of the air displaced by the balloon. assuming that the balloon is at sea level, where the air density is 0.002377 slug/ft3, calculate the maximum weight that can be lifted by the balloon. note: the molecular weight of air is 28.8 and that of helium is 4.

Me with this and you will be marked brainliest

Scientist have use computer models to create a series of maps that show how susceptible coastal cities in island countries are to the sea rising at different levels.the map shows that a 1 meter rise would swap cities all along the us eastern seaboard. a 6-meter sea level rise with sub merge a large part of florida. thermal expansion has already raise the oceans 10 to 20 centimeters the most likely cause,directly and indirectly, for such a rise in sea level is