(a) Calculate the change in entropy of a block of copper at 25 8C that absorbs 65 J of energy from a heater. (b) If the block of copper is at 100. 8C and it absorbs 65 J of energy from the heater, what is its entropy change? (c) Explain any difference in entropy change.

You've already seen the value of 9.8 in this lesson. what's this value called? what quantity does it represent?

Asimple electrochemical cell contains two electrodes.

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