At its ames research center, nasa uses its large "20 g" centrifuge to test the effects of very large accelerations ("hypergravity") on test pilots and astronauts. in this device, an arm 8.84 m long rotates about one end in a horizontal plane, and an astronaut is strapped in at the other end. suppose that he is aligned along the centrifuge’s arm with his head at the outermost end. the maximum sustained acceleration to which humans are subjected in this device is typically 12.5g. how fast must the astronaut's head be moving to experience this maximum acceleration? what is the difference between the acceleration of his head and feet if the astronaut is 2.00 m tall? how fast in rpm (revolutions per minute) is the arm turning to produce the maximum sustained acceleration?

Which term best describes the phrase “something that happens”?

Classify the following soils according to the uscs classification system. provide appropriate uscs designations. a) this sample of well-graded gravel with sand was obtained from a large earthen dam in vancouver, canada. the sample has 73% fine to coarse sub-angular gravel, 25% fine to coarse sub-angular sand and 2% fines. the maximum size of the particles is 75 mm. the coefficient of curvature is 2.7, while the uniformity coefficient is 12.4. b) this dark brown and wet soil with a “strong organic odor” has 100% passing the no. 200 sieve. the liquid limit of the material is 32% when not dried and is 21% when oven-dried. the plastic index is 21% when not dried. c) this sand has 61% predominantly fine sand, 23% silty fines, and 16% fine sub-rounded gravel size. the maximum size is 20 mm. the liquid limit is 33% and the plastic limit is 27%. d) this soil has 74% fine to coarse sub-angular reddish sand and 26% organic and silty dark brown fines. the liquid limit is 37% when not dried and is 26% when oven dried. the plastic index is 6% when not dried.

Determine the fraction of the magnitude of kinetic energy lost by a neutron (m1 = 1.01 u) when it collides head-on and elastically with a target particle at rest which is 21h (heavy hydrogen, m = 2.01 u).