We often use a spoon to cool coffee by stirring. Some of the heat is conducted from the coffee to the air by this method, but the spoon itself will cool the coffee a little. If a 12 gram aluminum teaspoon at 22 o C is placed in 175 ml of water (coffee's specific heat is close to water's) at 85 o C, what will the final temperature be? (Other factors, such as heat transfer to the air, may be ignored.)

Question 23 options:

78oC

92oC

84o C

82oC

Explanation:

heat lost by coffee = heat gain by aluminum spoon

heat lost by coffee = mc ( 85° C - T)

175 ml of water = 175 grams

175 grams = (175 / 1000) kg = 0.175 kg

heat loss by coffee = 0.175 × 4182 J/Kgk ( 85 - T) = 731.85 ( 85-T) = 62207.25 - 731.85 T

heat gain by aluminum spoon = 0.012kg × 897 J/kgK ( T - 22) = 10.764 T - 236.808

10.764 T - 236.808 = 62207.25 - 731.85 T

10.764 T + 731.85 T = 62207.25 + 236.808

T = 84.086 ° C approx 84°C

answer: the direction of the wind is expressed as the direction from which the wind is blowing. for example, easterly winds blow from east to west, while westerly winds blow from west to east.

explanation:

increasing transnational kinetic energy. because the transnational kinetic energy formula consists of only two variables, mass and velocity, increasing one of those properties is the only way to increase an object's transnational kinetic energy. increases to mass and velocity, however, do not have the same impact.