Question

A small 32 g water sample A is heated for 157 seconds by a 16 Watt heater resulting in an increase temperature capital delta T subscript A . The heated small water sample A is added to a larger tank of water, sample B, but, during the pouring process, water sample A cools down by 10% (a 10% decrease in the capital delta T subscript A ). The larger tank of water sample B was originally 363 g of water, before sample A was added. What is the final temperature change capital delta T subscript A plus B end subscript of the combined samples? Units are in degrees Celsius; do not include units in your answer. Use Cp = 4.1813 J/goC, and give your answer to two decimal places.

Answer 1

Energy supplied, Q = 16 x 157 = 2512 J

Q = m C deltaT

2512 = 32 x 4.183 x deltaT

deltaT = 18.77 deg C

now 2512 = (32 + 363) x 4.183 x deltaT

deltaT = 1.52 deg C