Question

18) 10 J of heat are removed from a gas sample while it is being compressed by a piston that does 30 J of work. Determine, in J, the change in thermal energy of the system.

a) 4

b) 10

c) 20

d) 3

Answer_______________

19) It is possible for a device to transform a given amount of heat completely into work.

a) true

b) false

Answer_______________

20) The density of a block of iron is 7,860 kg/m³. The density of mercury is 13,950 kg/m³.      This block of iron will:

a) float in mercury

b) sink in mercury

c) hang motionless in mercury

d) none of the above

Answer_______________

Answer 1

solution 78 heat removed I 10J work done = 3-J Heat supplied o = 30t10 4oJ Heat supplied = change in Internal twork done Energy Autw e = Yo = sut 30 ou = 10 J

solution (19 False. It is not possible for advice to transform a given amount of heat completely into work. solution density of block density of block = 7,860 Kg/m3 density of mercury = 13,950 kg/m3 density of block < density of mercury. since, So, according to Archimedes principle block of Iron a Float in Mercury