exam3
問題一覧
1
Water freezes at 0°C and 32°F, and boils at 100°C and 212°F.
2
Temperature is a measure of the average translational KE per molecule
3
Water freezes at 273 K and boils at 373 K
4
Energy transfers from warmer objects to cooler objects.
5
Hot objects contain thermal energy, not heat.
6
Heat is thermal energy that flows from hot to cold locations.
7
Heat is measured in joules because it is a form of energy transfer.
8
Heat is measured in joules because it is a form of energy transfer.
9
The energy needed is 4.19 J
10
The energy needed is 4.19 J.
11
Thermal energy can move from lower to higher temperatures only when external work is done on the system
12
Entropy is a measure of disorder. When a system’s disorder increases, its entropy increases.
13
The entropy of a system can decrease when work is done on it.
14
Evaporation is a phase change at the surface of a liquid; boiling is a phase change that occurs throughout a liquid, producing bubbles
15
The strip bends due to its two metals with difference rates of thermal expansion.
16
Ice is less dense than water due to its ice crystals that have open structures.
17
Q = cm∆T = (1 cal/g×°C)(300 g)(30°C – 20°C) = 3000 cal
18
Since Celsius degrees are larger than Fahrenheit degrees, an increase of 1 C° is larger, actually 9/5 as large
19
Thermal energy flows from a hot region toward a cooler region. That flow is called heat.
20
The brick will cool off too fast and you’ll be cold in the middle of the night. A jug of hot water with its higher specific heat will keep you warmer through the night.
21
No, the different expansions are what bends the strip or coil. Yes, it is important for without the different rates of expansions a bimetallic strip would not bend when heated (or when cooled
22
If they expanded differently, as for different materials, the fit between the lock and key wouldn’t match.
23
Cool the inner glass and heat the outer glass. If it’s done the other way around the glasses will stick even tighter (if not break)
24
The combined volume of all the billions of “open rooms” in the hexagonal ice crystals of a piece of ice is equal to the volume of the part of the ice that extends above water when ice floats. When the ice melts, the open spaces are filled in by the amount of ice that extends above the water level. This is why the water level doesn’t rise when ice in a glass of ice water melts—the melting ice “caves in” and nicely fills the open spaces.
25
The nucleus and its protons are positively charged; electrons are negatively charged
26
The charges are identical for all electrons.
27
The masses of electrons are much less than the masses of protons (1/2000th)
問題一覧
1
Water freezes at 0°C and 32°F, and boils at 100°C and 212°F.
2
Temperature is a measure of the average translational KE per molecule
3
Water freezes at 273 K and boils at 373 K
4
Energy transfers from warmer objects to cooler objects.
5
Hot objects contain thermal energy, not heat.
6
Heat is thermal energy that flows from hot to cold locations.
7
Heat is measured in joules because it is a form of energy transfer.
8
Heat is measured in joules because it is a form of energy transfer.
9
The energy needed is 4.19 J
10
The energy needed is 4.19 J.
11
Thermal energy can move from lower to higher temperatures only when external work is done on the system
12
Entropy is a measure of disorder. When a system’s disorder increases, its entropy increases.
13
The entropy of a system can decrease when work is done on it.
14
Evaporation is a phase change at the surface of a liquid; boiling is a phase change that occurs throughout a liquid, producing bubbles
15
The strip bends due to its two metals with difference rates of thermal expansion.
16
Ice is less dense than water due to its ice crystals that have open structures.
17
Q = cm∆T = (1 cal/g×°C)(300 g)(30°C – 20°C) = 3000 cal
18
Since Celsius degrees are larger than Fahrenheit degrees, an increase of 1 C° is larger, actually 9/5 as large
19
Thermal energy flows from a hot region toward a cooler region. That flow is called heat.
20
The brick will cool off too fast and you’ll be cold in the middle of the night. A jug of hot water with its higher specific heat will keep you warmer through the night.
21
No, the different expansions are what bends the strip or coil. Yes, it is important for without the different rates of expansions a bimetallic strip would not bend when heated (or when cooled
22
If they expanded differently, as for different materials, the fit between the lock and key wouldn’t match.
23
Cool the inner glass and heat the outer glass. If it’s done the other way around the glasses will stick even tighter (if not break)
24
The combined volume of all the billions of “open rooms” in the hexagonal ice crystals of a piece of ice is equal to the volume of the part of the ice that extends above water when ice floats. When the ice melts, the open spaces are filled in by the amount of ice that extends above the water level. This is why the water level doesn’t rise when ice in a glass of ice water melts—the melting ice “caves in” and nicely fills the open spaces.
25
The nucleus and its protons are positively charged; electrons are negatively charged
26
The charges are identical for all electrons.
27
The masses of electrons are much less than the masses of protons (1/2000th)