Question

A 3 Kg lead ball is dropped into a 3 L insulated pail of water initially at 20.0 degrees C. If the final temperature of the water-lead combination is 25 degress C, what was the initial temperature of the lead ball?

Answer 1

the sum of the heats gained is zero.

heat gained by water+heat gained by Pb =0
3000*Cw(Tf-20)+3*Cpb*(Tf-Ti)=0
solve for Ti lead.

Answer 2

69 degrees