Chapter 15 Physics
Compared to a giant iceberg, a hot cup of coffee has
higher temperature, but less internal energy
If the temperature of a sample of water at 4°C is slightly increased, its volume
increases
Why do substances expand when their temperature is increased?
because higher temperature substances have greater molecular motion
When most substances are heated, molecules inside move faster and take up more space, resulting in thermal _____________.
expansion
When you touch a cold piece of ice with your finger, energy flows
from your finger to the ice
A substance that heats up relatively slowly has a
high specific heat capacity
If glass expanded more than mercury, then the column of mercury in a mercury thermometer would fall when the temperature
increases
If the temperature of a sample of water at 4°C is slightly lowered, its volume
increases
Does a hot object contain internal energy or does it contain heat?
internal energy
Aluminum has a higher specific heat capacity than iron. This means that for equal masses of aluminum and iron, the metal that heats more quickly when the same amount of heat is applied is
iron
Heat energy is measured in units of
joules and calories
Hot sand cools off faster at night than plants and vegetation. This indicates that the specific heat capacity for sand is ___________.
less than that of plants
During a very cold winter, water pipes sometimes burst due to
water expanding when freezing
Why is the temperature fairly constant for landmasses surrounded by large bodies of water?
water has a high specific heat capacity
How does the specific heat capacity of water compare with the specific heat capacities of other common materials?
water has a higher specific heat capacity than most other common materials
How is the energy value of foods determined?
The food is burned and the energy released is measured.
Which temperature scales have equal sized degrees?
Celsius to Kelvin
Which unit represents the most energy? (calorie or joule)
calorie
At what temperature do the combined effects of contraction and expansion produce the smallest volume for water?
4C
Before ice can form on a lake, all the water in the lake must be cooled to
4C
Why is ice less dense than water?
Ice crystallizes with an open structure, and the gaps that form between the water molecules in ice increase its volume.
The fact that desert sand is very hot in the day and very cold at night is evidence that the specific heat capacity of sand is relatively
low
A substance that cools down faster than others has a
low specific heat capacity
A substance that heats up relatively quickly has a
low specific heat capacity
White-hot sparks from a 4th-of-July-type sparkler that strike your skin have relatively
low transfer of energy, high temperatures, few molecules per spark, (all of the above)
Ice tends to form first at the
surface of bodies of water
Tomatoes have a higher specific heat capacity than dough. This means that when you bite into a hot pizza
the tomato sauce feels hotter than the dough
The fact that a thermometer "takes its own temperature" illustrates
thermal equilibrium
The kind of molecular motion that mostly relates to the temperature of a substance is
transnational motion
