Which of the following processes would be the closest to reversible? A. a book that slides across a rough carpeted floor
B. hot water that is forced through a pipe at high velocity
c. a fan that operates at high speed pumping hot indoor air into the surrounding environment outside
D. a piston that expands slowly against a well-greased metal cylinder

Acarpenter is driving a 15.0-g steel nail into a board. his 1.00-kg hammer is moving at 8.50 m/s when it strikes the nail. half of the kinetic energy of the hammer is transformed into heat in the nail and does not flow out of the nail. what is the increase in temperature of the nail after the three blows that the carpenter needs to drive the nail in completely? the specific heat of steel is 448 j/kg ∙ k. a) 2.7 k b) 1.8 k c) 7.7 k d) 8.1 k e) 3.6 k