Physicah

Name 3 units for measuring heat.

Name 3 units for measuring heat.

thermal insulator conductors

wood,Styrofoam and plastic

When you hold a cold glass of water in your warm hand, which way does the heat flow?

Heat flows naturally from a warmer object (higher energy) to a cooler one (lower energy).

thermal equilibrium

When 2 objects are at the same temperature and no heat flows

As you add thermal energy to an object its temperature will increase. Name two factors that will affect how much the temperature of a substance will change.

mass,specific heat

1 kilocalorie

1,000 calories

1 Btu

1,055 joules

1 Btu

252 calories

1 calorie

4.186 joules

The warm air from the equator doesn't make it all the way to the poles because of Earth's rotation. In fact, the combination of global convection and Earth's rotation sets up a series of wind patterns called global wind cells in each hemisphere ( These cells play a large role in shaping weather patterns on Earth.

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Warm air at the equator tends to rise and flows toward th e poles.

Cooler, denser air from the poles sinks and flows back toward the equator.

Thermal Radiation

Electromagnetic waves produced by objects because of their temperature

The amount of thermal energy in an object depends on what two factors?

Mass (amount of matter) and temperature. If two pots of water are heated to the same temperature, the larger pot will have more energy than the smaller one.

On a night at the beach, which would you expect to cool faster: the ocean water or the beach sand?

Sand gets warmer than the ocean during the day, therefore it cools faster at night. Sand doesn't retain heat as easily as water, and will fluctuate drastically in temperature from too hot to walk on, to cold, while the ocean stays cool to cold.

specific heat

The amount of heat needed to raise the temperature of 1 kilogram of a material by 1 degree celsius

Why does specific heat vary for different substances?

The temperature increase of an object depends on its mass and the material from which it is made. Elements made of heavier atoms tend to have lower specific heats, since temperature measures the average kinetic energy per atom and there would be fewer atoms/kg.

Heat Conduction

The transfer of heat by the direct contact of particles of matter

convection

The transfer of heat by the motion of matter, such as moving air or water

Distinguish between heat and thermal energy.

Thermal energy /Internal energy of an object refers to the sum of kinetic energy(translation +rotational +vibrational) and potential energy (bond energy) of molecules. Heat is energy in transit. Heat cannot be stored. It is transfered from an object at higher temperature to a body at lower temperature.

Heat

Thermal energy that is moving or is capable of moving

There are also giant convection currents in the atmosphere.

These form as a result of the temperature difference be tween the equator and the poles.

These currents move slower than surface currents and are driven by temperature and density difference s in the ocean. Surface and deep currents work together to move huge masses of water around the globe. Ocean currents play a big role in heating and cooling some parts of Earth.

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The temperature increase of an object depends on:? a. its mass b. its velocity c. the material from which it is made d. answers a and c e. none of the above

a,c

Which material would have a higher specific heat: a. a material made of heavier particles b. a material made of lighter particles c. the mass of the particles doe s not affect specific heat

b

ways tranfers may occur

coduction, convection and radiation

two properties that increase an objects ability to absorb radiation

color, dull surface

explain the difference between calorie in energy and in food

energy calorie is an actual calorie and nutrient calorie is a kilo calorie

two substance that make good thermal conductors

gold and cooper

The global wind patterns and Earth's rotation cause surface ocean currents to move in large circular patterns. Ocean currents can also occur deep within the ocean.

iii

black absorbs , white______

reflects

best state conductor

solid

heat conduction example

spoon in a cup of hot chocolate

Heat Transfer

the flow of thermal energy from higher temperature to lower temperature

sun-earth

thermal energy

When air flows horizontally from an area of high density and pressure into an area of low density and pressure,

we call the flowing air wind