An 8 000-kg aluminum flagpole 100-m high is heated by the sun from a temperature of 10°c to 20°c. find the increase in internal energy (in j) of the aluminum. (the coefficient of linear expansion is 24 × 10 −6 (°c) −1 , the density is 2.7 × 10 3 kg/m 3 , and the specific heat of aluminum is 0.215 cal/g⋅°c.) a. 7.2 × 10 5 b. 7.2 × 10 7 c. 7.2 × 10 3 d. 7.2 × 10 1 e. 7.2 × 10 2