Physics Ch 15,17,19,20

What is the celsius scale?

named after anders celsius, 0 degrees for freezing point to 100 degrees for boiling point

What is the specific heat capacity?

quantity of heat required to change the temp of a unit mass of the substance by 1 degree C

How does the sun transfer energy?

radiation, radiates energy to people leading to heat, sun energy travels to earth and doesn't need a median

The vibrations of a longitudinal wave move in a direction

along the direction of wave travel.

Like a transverse wave, a longitudinal wave has

amplitude, frequency, wavelength, and speed

Which of the following normally warms up fastest when heat is applied? -water -iron -glass -wood -All of the above choices are equally true.

iron

Your feet feel warmer on a rug than on a tile floor because a rug

is a better insulator than tile.

When the air pressure is lowered

it takes less heat to boil water.

When an iron ring is heated, the hole becomes

larger.

What is the Fahrenheit scale?

named after g.d fahrenheit, 32 degrees for freezing to 212 degrees for boiling

If you heat an ice bucket of water for several hours until only a small amount of ice remains, the temperature of water will be

0 degrees C

What is temperature?

a number that corresponds to the warmth or coldness of an object

A standing wave occurs when

a source wave and its reflected wave are in phase.

Warm air rises because faster-moving molecules tend to move to regions of less

density and less pressure.

What is a thermometer?

device used to measure temp by expansion/contraction of a liquid (mercury or colored alcohol)

What is thermal expansion?

due to rise in temp of a substance, molecules move faster and move further apart more substances expand when heated and contract when cooled

What is the spectrum?

graph with frequencies ranging from high to low, and short to long wavelengths. People see the visible light, longer wavelength= red , shorter wavelength= blue

Which of the following expands most when the temperature is increased? Equal volumes of

helium

The moderate temperatures of islands throughout the world has much to do with water's

high specific heat

Which of the following is not a transverse wave?

sound

Wave interference occurs for

sound waves, light waves, and water waves

What is a simple pendulum?

suspending a stone at the end of a piece of string, swinging to and fro at rate

Both black and white road surfaces absorb sunlight. At the end of a sunny day the warmer road surface will be

the black surface.

What does it mean if temperature is a per particle property?

the kinetic energy is per particle; if particles move fast= high temp, if particles move slow= low temp

What are the types of waves?

transverse (perpendicular) and longitudinal (parallel)

The food in a refrigerator is cooled by

vaporization of the refrigerating fluid.

How many joules does it takes to vaporize 1 gram of water?

2255J

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.

What is a wave description?

a since curve is obtained when you trace out the path of a vibrating pendulum over time and a bob vibrates up and down

When you touch a cold piece of ice with your finger, energy flows

from your finger to the ice.

What does it mean when land has a lower specific heat capacity?

gets hot in the summer and cold in the winter

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

gives up change of phase energy when it condenses and has more energy per kilogram than boiling water.

As atmospheric pressure is increased, the boiling temperature of a liquid

goes up.

examples of thermal expansion

railroad tracks, metal lids on glass jars, expansion joints on bridges, gaps on concrete roadways and sideways

The planet Earth loses heat mainly by

radiation

If you add heat for 35 minutes to a pan with 2 kgs of 100°C water in it the temperature of the remaining water will be

100 degrees C

An object that completes 20 vibrations in 10 seconds has a frequency of

2 hertz

What is the heat of fusion for water? What is the heat of vaporization for water?

334 J/g or 80 cal/g 540 cal or 2256 j/g

What is the Kelvin scale?

after lord kelvin, -273 degrees for freezing to 373 degrees for boiling, 0 K is absolute zero

The vibrations of a transverse wave move in a direction

at right angles to the direction of wave travel.

How is boiling a cooling process?

boiling water is being cooled as fast as it is being warmed

Which body glows with electromagnetic waves?

both the Sun and the Earth

What does it mean if something is a good conductor?

can conduct heat quickly, substances with loosely held electrons ex. silver, copper

What is sublimation?

change from solid to gas (ice to water vapor)

What is the Doppler Effect?

changes in sound frequency when a cource moves towards or away from you

What are the 3 ways to transfer heat?

conduction, convection, radiation

What are longitudinal waves?

consists of waves being compressed

What is Newton's Law of Cooling?

cooling is approx. proportional to the temp difference between the object and its surroudings

When a bimetallic bar made of copper and iron strips is heated, the bar bends toward the iron strip. The reason for this is

copper expands more than iron

What are the parts of a wave?

crest- high points troughs- low points amplitude- distance from midpoint to the crest/trough wavelength- distance between successive identical parts of wave frequency- # of vibrations in a given time

A Doppler effect occurs when a source of sound moves

either towards you or away from you.

When warm air rises, it

expands and cools

Compared to a glass of ice water with ice in it, on a warm day a glass of pure ice-cold water without ice will warm up

faster

What is the flow of internal energy?

flow from high temp substance to low temp substance until thermal equilibrium is reached

Energy transfer by convection is primarily restricted to

fluids.

Where does heat transfer with hot objects? With cold objects?

from hot object to body; from body to cold object

Food in a pressure cooker is cooked faster because of the

higher temperatures reached in a sealed container.

An object will normally be a net radiator of energy when its temperature is

higher than its surroundings.

What are standing waves?

incident wave and reflected wave, particular points are fixed (nodes, antinodes)

What are poor conductors?

insulators, substances with tightly held electrons ex. glass, wool, paper, wood

What does it mean when water has a higher specific heat capacity?

it tends to resist changing in temperature

If we slowly pump out all the air over a bowl of water until it is in a vacuum,

it will boil, then freeze.

The frequency of a simple pendulum depends on

its length and the acceleration due to gravity

Heat energy is measured in units of

joules and calories

Metals are both good heat conductors and good electrical conductors because of the

looseness of outer electrons in metal atoms.

A substance that heats up relatively quickly has a

low specific heat

Adding pressure to ice causes ice to

melt

A node is a position of

minimum amplitude

What is evaporation?

molecules that move rapidly escape water and take away energy

What are temperature limits?

no upper limit, definite lower limit (-273 degrees C)

What is the absorption of radiant energy?

occurs along emission of radiant energy, effects of surface of material on radiant energy, net absorption is relative to temp of surroundings, good absorbers are good emitters

What is wave interference?

occurs when 2 or more waves interact with each other, occur at the same place and same time

What makes ice less dense than water?

open structured crystals resulting from strong bonds of certain angles that increase its volume increase in temp= decrease in volume

What is boiling?

rapid evaporation beneath the surface forming water bubbles, boiling point depends on pressure; 100 degrees C is thermal equilibrium

To say that one wave is out of phase with another is to say that the waves are

reaching maximum amplitude at different times.

When a gas is changed to a liquid state, the gas

releases energy.

What is thermal inertia?

resistance of a substance to change in temp

Examples of transverse waves

ripples in pond, vibrations in musical instruments, radio waves, light waves

The higher the temperature of an object

shorter the wavelengths it radiates.

The pendulum with the greatest frequency is the pendulum with the

shortest length.

What is the greenhouse effect?

the trapping of the sun's warmth in a planet's lower atmosphere

What does it mean if a particle is frozen?

there is no movement, temperature is absolute 0

What is the period in a pendulum?

time of one cycle (one swing) to complete , period depends on length of string

What is radiation?

transfer of heat by electromagnetic waves; doesn't involve movement or interaction of matter

What is conduction?

transfer of heat involving only motions of fluids (fluid flow)

A wiggle in time, but not in space, is a

vibration

When water in the vapor phase condenses to liquid in the air, the surrounding air

warms

What does it mean for water if there is lower pressure?

water is easier to boil

The Doppler effect is characteristic of

water waves, sound waves, and light waves

When does a reading occur on a thermometer?

when thermometer and object reach thermal equilibrium

What is the expansion of water?

when water becomes ice, it expands

What is a wave?

wiggle in space and time, extends from one place to another

How do you measure temperature?

with a thermometer

Before ice can form on a lake, all the water in the lake must be cooled to

4 degrees C

The technology for orbiting solar power plants

Already exists

What is the superposition principle?

The displacement due the interference of waves is determined by adding the disturbances produced by each wave.

What is conduction?

The process where vibrating particles transfer energy to neighboring particles (particle collision)

What is heat?

internal energy transferred from one thing to another due to a temperature difference

What is the reflection of radiant energy?

opposite to absorption of radiant energy, any surface that reflects little or no radiant energy looks dark, good reflectors are poor absorbers