Physics Set 3
Lead sinkers actually float on the surface of liquid mercury. Which takes up more space: 1 kg of mercury or 1 kg of lead?
Lead
Suppose you try to cool your home in the summer by letting heat flow from your house to your neighbor's home. You will
Not get far, because of the zeroth law of thermodynamics
"The entropy of an isolated system never decreases." Which Law of Thermodynamics is this?
Second
When you touch a cold piece of ice with your finger, energy flows
from your finger to the ice.
Steam burns are more damaging than burns caused by boiling water because steam
gives up additional energy when it condenses. has more energy per kilogram than boiling water.
For increased atmospheric pressure, the boiling temperature of a liquid
goes up.
When water vapor condenses on the inside of a window, the room becomes slightly
warmer.
Which could burn the most?
100 g of steam at 100 degrees C
If you double the absolute temperature of a star, its power output increases by a factor of
16
If you double the radiating surface area of a star, its power output increases by a factor of
2
Before ice can form on a lake, all the water in the lake must be cooled to
4 degrees C.
Why are good thermal conductors generally good electric conductors also?
Electron motion is responsible for determining both properties.
Which of the following quantities is not conserved?
Entropy
Why does an ice cube feel cold?
Heat from your hand enters the cube by conduction.
A shiny, white transparent surface prevents heat transfer because
It has emissivity of zero and reflects all light that strikes it.
The fact that desert sand is very hot in the day and very cold at night is evidence that sand has
a low specific heat.
Near the top of a mountain, water in an open pot boils at
a lower temperature than at sea level.
When a solid is changed to a liquid state, the solid
absorbs energy.
Pour a liter of water at 40 degrees C into a liter of water at 20 degrees C and the final temperature of the two becomes
at or about 30 degrees C.
The first law of thermodynamics is a re - statement of the law of
conservation of energy
The gulf stream is one of nature's ways of transferring energy through
convection.
Wind is one of nature's ways of transferring energy through
convection.
Melting snow
cools the surrounding air.
Ice is put in a cooler to cool the contents. To speed up the cooling process, the ice can be
covered with salt.
Consider a sample of ice at 0 degrees C. If the temperature is decreased, the volume of the ice
decreases.
Consider a sample of water at 0 degrees C. If the temperature is slightly increased, the volume of the water
decreases.
When heat is added to boiling water, its temperature
does not change.
Two equal-sized buckets are filled to the top with water. One of the buckets has a piece of wood floating in it, making its total weight
equal to the weight of the other bucket
When water at 4 degrees C is heated slightly it expands. When water at 4 degrees C is cooled slightly, it
expands
Compared to a glass of ice water with ice in it, a glass of plain ice-cold water without ice on a warm day will warm up
faster.
Which of the following normally warms up fastest when heat is applied?
iron
Heat energy is measured in units of
joules and calories
When an iron ring is heated, the hole becomes
larger.
If the specific heat of water were lower than it is, ponds in the cold of winter would be
more likely to freeze.
Food cooked in boiling water at a mountain top cooks slower than when cooked at sea level. If the temperature under the pot of boiling water is increased, the food will cook
no differently than it did before the increase.
When liquids change to a solid state, they
release energy.
When a gas is changed to a liquid state, the gas
releases energy.
Ice tends to form first at the
surface of bodies of water.
Housing and natural animal insulation works because
the insulating materials trap air and prevent convection.
Evaporation is a cooling process because
the more energetic molecules are able to escape the liquid.
When cooking a potato in a conventional oven it is useful to stick a nail in it, which makes it cook faster. This is because
the nail is a good conductor of heat
The fact that a thermometer "takes its own temperature" illustrates
thermal equilibrium.
Suppose you walk on red-hot coals with bare feet. If bits of the coals do not stick to your feet, it would be best if your feet are
wet.
