Question

Problem 3-2-9 The heat transfer necessary to raise the temperature of a constant-volume closed system is given by Q=AU. Using the SL model compare the heat necessary to raise the temperature by 10°C for such a system of 2 kg and composed of (a) gold, (b) iron. (c) sand, and (d) granite Part A Gold Express the heat in kilojoules to three significant figures. Q = 2.58 kJ Submit Previous Answers ✓ Correct Part B Iron Express the heat in kilojoules to two significant figures. Q = 9.0 kJ Previous Answers ✓ Correct - Part C Sand Express the heat in kilojoules to one significant figure. Temgiates Symbols slope Displacement vector Undo redo Reset keyboard shortcuts help Q = 10 Submit Previous Answers Request Answer X Incorrect: Try Again: 2 attempts remaining Part D Granite Express the heat in kilojoules to four significant figures. Temgiates Symbols sigpe Displacement Vector Undio redio Teset keyboard shortcuts help Q= 1.60.101 Submit Previous Answers Request Answer

Answer 1

given mass m = 2 kg

ΔT  = 10^oC

Part A )

GOLD :

using equation

Q = m C ΔT

= 2 x 0.129 x 1000 x 10

Q = 2580 J

Q = 2.58 KJ

Part B )

IRON :

Q = 0.45 x 2 x 1000 x 10

Q = 9 kJ

Part C )

SAND :

Q = 2 x 1000 x 10 x 0.835

Q = 16700 J

Q = 16.7 kJ

Part D )

GRANITE :

Q = 2 x 1000 x 10 x 0.79

Q = 15800 J

Q = 15.8 kJ