Question

Show all working and calculations for multiple choice given

5) a) In a cloud formation, water vapor condenses into water droplets which get bigger and bigger until it rains. This will cause the temperature of the air in the clouds to

A) increase.

B) decrease.

C) stay constant.

D) freeze.

b) Equal masses of water at 20°C and 80°C are mixed. What is the final temperature of the mixture?

A) 40°C

B) 50°C

C) 60°C

D) 70°C

c) Which of the following best explains why sweating is important to humans in maintaining suitable body temperature?

A) Moisture on the skin increases thermal conductivity, thereby allowing heat to flow out of the body more effectively.

B) Evaporation of moisture from the skin extracts heat from the body.

C) The high specific heat of water on the skin absorbs heat from the body.

D) Functioning of the sweat glands absorbs energy that otherwise would go into heating the body.

d) 16.5 kcal of heat is equivalent to how much work?

A) 3.94 J

B) 3940 J

C) 69.1 J

D) 69100 J

e) 150 kcal of heat raises the temperature of 2.0 kg of material by 400 F°. What is the material's specific heat capacity?

A) 1.35 kcal/kg∙ °C

B) 0.75 kcal/kg∙ °C

C) 0.34 kcal/kg∙ °C

D) 0.19 kcal/kg∙ °C

Answer 1

a Clouds form when the water vapor condenses into small particles. As a parcel of air rises, the moisture it contains cools and condenses out onto small particles of dust called cloud condensation nuclei until a cloud forms. As a volume of unsaturated air cools, its relative humidity increases.

Correct answer is B.