How much heat is absorbed by a 2000 kg granite boulder as energy from the sun causes its temperature to change from 10°C to 29°C?

2 Answers
Apr 24, 2017

Answer:

3.002 MJ

Explanation:

Heat absorbed,
#H= m.c. del(theta)#
Where, m= mass,
C= specific heat capacity. Assume #c=790 J/(kg)/K# for granite.
#del(theta)# is the change in temperature.
Hence, #del(theta)=29-10=19K#

(Note: For difference of temperature, Celsius degrees and Kelvin are interchangeable, as the interval for both scales is the same.)

Then we have,
#H=2000*790*19 = 3002000 J = 3.002 MJ#

Apr 24, 2017

Apply the equation

#color (red)(Q = mCpDeltaT)#

#color(blue)("Where Q is heat absorbed")#

#color(blue)("Cp is the specific heat")#

#color(blue)(DeltaT "is " t_"final" - t_"initial"#

#color(blue)("m is mass in grams")#

The #Cp# of granite

#Cp# of granite is #"0.79J/g"*C^@#

Convert 2000kg to grams = #2*10^6g#

#2*10^6g xx "0.79J/g"*C^@ xx (29C^@-10C^@) = 30 020 000J#