An iron piston in a compressor has a mass of 3.62 kg. If the specific heat of iron is 0.449 J/g°C, how much heat is required to raise the temperature of the piston from 12.0°C to 111.0°C?

I got Q=3620(4.184)(99) which equals 160.91 but the answer is 1.61x10^5. Where did I go wrong?

1 Answer
Dec 5, 2017

#DeltaE=1.61*10^5J#

Explanation:

#DeltaE=mcDeltatheta#, where:

  • #DeltaE# = change in energy (#J#)
  • #m# = mass of the object (#kg#)
  • #c# = specific heat capacity of the object (#J# #kg^(-1)# #K^(-1)#)
  • #Deltatheta# = change in temperature (#K#)

#0.449J # #g^(-1)# #""^circC^(-1)# #= 449J# #kg^(-1)# #K^(-1)#

#Deltatheta = 111-12=99^circC#

As #Delta""^circC=DeltaK#

#Deltatheta=99K#

#DeltaE=3.62*449*99=160912.62J=1.6091262*10^5J~~1.61*10^5J#