Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

. While playing pong, you can’t find a ping pong ball, so a friend suggests usin

ID: 695144 • Letter: #

Question

. While playing pong, you can’t find a ping pong ball, so a friend suggests using a golf ball. During the game, you throw the golf ball weighing 42.9 g at 25.0°C into a cup containing 300 g of water at 4.0°C. If the final temperature of the system is 11.0°C, what is the heat capacity of the golf ball in J/°C? Assume that the water has a heat capacity of 4.20 J/g°C, and that the heat capacity of the cup is negligible. (1) 14.7 J/°C (2) 180 J/°C (3) 630 J/°C (4) 206 J/°C (5) 8820 J/°C

The answer is 630 J/C. I just need an explanation.

Explanation / Answer

The energy balance

-warm golf ball = cold water

heat of golf ball = Cpball*(Tf-Tball)

heat of water = mwater*Cpwater*(Tf-Twater)

substitute

-Cpball*(Tf-Tball) = mwater*Cpwater*(Tf-Twater)

-Cpball(11-25) = 300*4.184*(11-4)

Cball = 300*4.184*(11-4)/(-(11-25)) = 627.6J/°C

roundin up to 2 sig fig --> 630 J/C°