Ahot iron ball of mass 200 g is cooled to a temperature of 22°c. 6.9 kj of heat is lost to the surroundings during the process. what was the initial temperature of the ball? (ciron = 0.444 j/g°c)

An electric power distributor charges residential customers $0.10 per kilowatt-hour (kwh). the company advertises that "green power" is available in 150 kwh blocks for an additional $4 per month. (green power is generated from solar, wind power, and methane sources.) if a certain customer uses an average of 391 kwh per month and commits to one monthly 150 kwh block of green power, what is her annual power bill