Physics ch. 21-23

Which would burn the most?

100 g of steam at 100 degrees C

The number of calories released when 3 grams of 100 degrees Celsius steam cools to become 3 grams of 0 degrees ice is

2160 calories

An air sample contains 25% of the amount of water vapor it is capable of holding. The air's relative humidity is

25%

One thousand calories of heat are added to 150 grams of water when it's temperature is 33 degrees C. The resulting temperature of the water is

40 degrees C

The energy needed to turn 43 grams of 100 degrees Celsius boiling water to 100 degrees Celsius steam is

43 X 540 calories

Mix a liter of 70 degrees C water with 2 liters of 40 degrees C water and you'll have 3 liters of water at

50 degrees C

How much energy is released when 1 gram of steam condenses to water at 100 degrees Celsius?

540 calories

A change in temperature of 10 degrees C is equal to

A change of 10 K

A good absorber of radiation is

A good emitter of radiation

A good reflector of radiation is

A poor absorber of radiatoon

Evaporation is a cooling process and condensation is

A warming process

Temperature is related mostly to the

Average molecular kinetic energy in a substance

If you take a shower in a steamy bathroom and then go to your bedroom to dry off, why will you feel colder in your bedroom?

Because water evaporates off of your skin, your skin will be cooled

The energy content of a piece of food is normally determined by

Burning the food

Which temperature scale labels the freezing point of water at 0 degrees?

Celsius

Ice is put in a cooler to cool the food stores there. In order to speed up the cooling process, you should

Crush the ice

A bimetallic strip will bend when heated because

Each metal expands at different rates

A piece of paper wrapped around a thick metal bar will not ignite when touched with a lit match because

Energy goes to the bar, preventing ignition temperature in the paper. The bar keeps the paper relatively cool. The bar is slow to heat up.

Heat is the

Energy transferred between objects because of a temperature differnece

When water at 4 degrees C is heated, it expands. When water at 4 degrees C is cooked, it

Expands

Energy transfer by convection is primarily restricted to

Fluids

Condensation occurs when matter changes from a

Gas to a liquid

When water freezes it

Gives off energy

Steam burns are more damaging than burns caused by boiling water because steam

Has more energy per kilogram than boiling water

The largest extremes in temperature are usually experienced

In the middle of the continent

Plastic foam is a good heat

Insulator

At high altitudes, the boiling point of water

Is lower

A liquid boils when

It turns to vapor at the bottom of or in the liquid

Heat is measured in

Kilocalories, joules, calories

If the specific heat capacity of water were higher tha it is, lakes would be

Less likely to freeze

Evaporation takes place when matter changes from a

Liquid to gas

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 capacity

A piece of metal will feel colder than a piece of wood at the same temperature. Why?

Metals are good heat conductors

Specific heat capacity is related to the amount of internal energy

Needed to change the temperature of one gram of a substance one degree

Infrared radiation is a form of

Radiant energy

Heat travels from the sun to Earth by

Radiation

Planet earth loses heat primarily by

Radiation

The metallic coating on the glass surfaces of a Thermos vacuum bottle reduces the amount of energy transferred by

Radiation

The reason pressure cookers cook food faster is that they

Raise the cooking temperature of the food

The reason light colored clothes help keep you cool in warm weather is that clothes of light color

Reflect a lot of wnergy

When water vapor condenses on the inside of a window, the window becomes

Slightly warmwr

When heat is added to boiling water, the temperature of the boiling water

Stays the same

Two pots are filled with boiling water. The pots are exactly the same size, but one pot is white and the other is black. Which pot cools faster?

The black pot

To say that evaporation is a cooling process means that when evaporation occurs

The remaining liquid cools

On which day will the amount of water vapor in the air be greater, a summer day at 100% humidity or a winter day at 100% humidity?

The summer day

Newtons law of cooling says that the rate of cooling depends on

The temperature difference between an object and its surroundings

Internal energy is the

Total amount of energy contained in an object

The cooling effect inside a refrigerator is produced by

Vaporizing the refrigeration liquid

When snow forms in clouds, the surrounding air

Warms

Which has a higher specific heat capacity, water or sand?

Water

Which releases the most energy. 100 grams of 100 degrees C water cooling to 50 degrees C, or 100 grams of iron at 100 degrees C cooling to 50 degrees C?

Water

During a very cold winter, water pipes sometimes burst. The reason for this is

Water expands when freezing

The reason an ocean's temperature doesn't vary much from one season to the next is that

Water has a high specific heat capacity

Firewalkers who walk barefoot on red hot wooden coals depend on

Wood's poor conductivity

In a florist's greenhouse, glass acts as a one-way valve, letting

high frequency light in and preventing low frequency radiation from escaping