Transcript Q5 - Helios

Qwizdom Grading
(4% of your course grade)
1. Each correct answer = 2 points
2. Each incorrect answer or no answer = 1
3. Absent = 0 points
Suppose there are 40 questions during the term.
Some possibilities
Perfect – all correct
Always come to class
Never attend class
Come half the time
Points
80
40 – 80
0
20 – 40
% value
4
2–4
0
1–2
3. The amount of heat necessary to raise the
temperature of 1 gram of water by 1°C is
referred to as the
A. calorie
B. kilocalorie
C. British thermal unit
D. joule
3.
The correct answer is A, the calorie.
4. Which of the following is the smallest unit of
heat energy?
A.
B.
C.
D.
calorie
kilocalorie
Btu
joule
4.
1 kcal = 1000 cal
1 kcal = 4186 J
1 cal = 4.186 J
1 Btu = 252 cal
So the answer is D, the joule.
From smallest to largest: J, cal, Btu, kcal
5. A chunk of ice (T = -20°C) is added to a thermally
insulated container of cold water (T = 0°C). What
happens in the container?
A. The ice melts until thermal equilibrium is
established.
B. The water cools down until thermal equilibrium is
established.
C. Some of the water freezes and the chunk of ice
gets larger.
D. none of the above
5.
The correct answer is C, some of the water
freezes and the chunk of ice gets larger.
The final temperature must be between 0 and
-20°C. So more ice forms.
Done with Qwizdom