Heat and Temperature

PROJECT DONE BY, PRATHAM . N .GORANI GRADE -7 GLOBAL COMPASS

Temperature

• Temperature is a measure of the average Kinetic Energy of the particles in a substance.

– KE is the energy of motion.– The higher the average Kinetic Energy, the

faster the particles move– Temperature and Heat are NOT the same

thing

It is a variable to measure “hot” and “cold”. It is a measure of an internal kinetic energy

What is temperature?

Temperature Scales

• There are 3 Types of Temperature Scales

– Fahrenheit– Celsius– Kelvin

Celsius Fahrenheit

Fahrenheit Scale

• Most commonly used in United States. (originated in Great Britain)

• Non-metric system scale

• Not usually used in science

Gabriel Fahrenheit

How Fahrenheit Works

• Water freezes at 32°F• Water boils at 212°F

• Zero was based on the lowest they could get water to stay liquid at the time (with salt in it).

• 100° was based on the highest it was believed humans could survive at the time

Celsius Scale

• Based on Metric System Scale

• Most used in the world, including Canada, Europe, and Asia

Anders Celsius

How Celsius Works

• Water freezes at 0°C• Water boils at 100°C

• Absolute zero is -273°C

Kelvin Scale

• Actual Metric System scale.• Most often used in Laboratory

settings for calculation purposes.

• There are no negative temperatures.

• A change (Δ) of 1oC = 1 K.

William ThomsonBaron of Kelvin

Absolute Zero• Defined as 0 Kelvin.• Average temperature of space is 2.7K• Scientists have gotten within fractions of absolute

zero, but it is impossible to ever completely stop the movement of an atom, since that means it has zero energy.

Boomerang Nebula contains the coldest known temperature in the

universe at 1K

Helium can only become a gas at below 5K

Temperature Scale Comparisons

373 K = 100°C

37°C = 99°F298 K = 25°C

273 K = 0°C-40°C = -40°F

0 K = -273°C

What is heat?

The flow of thermal energy from one object to another. Heat always flows from warmer to cooler objectsIce gets warmer while hand gets cooler Cup gets cooler while hand gets warmer  

Heat Transfer

Conduction, Convection, and Radiation

Types of Heat Transfer

Conduction

Takes place between solids or solids with liquids

– Particles vibrating or moving faster transfer some of their energy to nearby atoms

ConductionWhen particles collide and the faster ones pass some

of their energy on to the cooler ones.

This results in a change in energy for each particle

This causes the faster ones to slow down and cool

The slower ones speed up and heat up

Examples of Conduction

Conduction requires direct contact

Convection

• Occurs in Fluids (liquids and gases)

• Caused by a change in density due to a change in temperature.

Convection • The warmer fluid

expands, becomes less dense and rises.

• The cooler fluid contracts, becomes more dense and sinks.

Lava Lamps are an example of convection that you have probably seen before.

Convection

Importance of Convection

Convection causes warm water vapor to rise, condense into clouds when it cools, and then falls back as rain

Without convection, there would be no rainfall and thus no plants

Examples of Convection

• Magma in the mantle rises due to convection.

• The heat from the core heats it and then it rises to form volcanoes on the surface

Radiation

• The transfer of energy due to Infrared and other electromagnetic rays.

• Radiation can travel through space.• All things radiate heat.

Why are light bulbs hot?

• They produce infrared radiation in addition to visible light

• Infrared transfers energy to the molecules that makes them vibrate faster (thus hotter)

Thermal Expansion• When objects heat up their particles move

faster, hit others harder, and bounce further, creating more empty space between the particles.

• As a result, the entire substance expands.• This is known as thermal expansion

Examples of Thermal Expansion

• Roads crack as they expand in the heat

• On bridges and other sensitive sections, expansion panels allow it to flex.

Thermal Expansion

• The liquid in a thermometer expands as it warms.

• This causes it to head up the tube and tell you the temperature

Heat Transfer

• Heat Conductors– Good thermal conductors transfer heat

rapidly– Metals are good thermal conductors

Radiators are metals that transfer the heat in the water to the air

Frying pans transfer heat from the stove to the food

Heat Transfer• Thermal Insulators

– Poor thermal conductors of heat.– Asbestos, cork, ceramic, cardboard, and

fiberglass are examples of thermal insulators

STATES OF MATTER UNDER DIFFERENT TEMPERATURE

The gas inside a balloon expands when heated.

Expansion and contraction in solid , liquid , gas .

The particles move more freely than in solids. Liquids usually expand more than soilds.

The particles are far apart and move more freely than in liquids. Gases usually expand more than liquids.

The particles are not free to move. Solids do not expand much.

Solids Liquids Gases

WHAT HAPPENS WHEN RAILS CONTRACT?

WHAT HAPPENS WHEN A GAS EXPANDS?

Mercury expands when heated.

Expansion joints expand when it is hot.

The gas inside a balloon expands when heated.

Expansion and contraction in solids

The particles move more freely than in solids. Liquids usually expand more than soilds.

The particles are far apart and move more freely than in liquids. Gases usually expand more than liquids.

The particles are not free to move. Solids do not expand much.

Solids Liquids Gases

WHAT HAPPENS WHEN A GAS EXPANDS?

Mercury expands when heated. Expansion

joints expand when it is hot.

The rails cool.

[close]

0 10

The particles move more slowly and occupy less space.

The volume decreases, and the rails contract.

0 10

The gas inside a balloon expands when heated.

Expansion and contraction

The particles move more freely than in solids. Liquids usually expand more than soilds.

The particles are far apart and move more freely than in liquids. Gases usually expand more than liquids.

The particles are not free to move. Solids do not expand much.

Solids Liquids Gases

WHAT HAPPENS WHEN RAILS CONTRACT?

Mercury expands when heated. Expansion

joints expand when it is hot.

When gas expands, the volume increases. This can push a cork out.

Gases

Changes of state

SOLID

LIQUID

GAS

mel

ting

solid

ifcat

ion

sublimation

desublimation

evaporation

condensation

endothermic

exothermic

Heat changes can be:

When a state of matter gains or loses heat, it undergoes a change.

Conduction

Direction of heat

The kinetic energy of the particles increases.

particles of a solid

This is the transfer of heat in most solids.

Heat is transferred

by direct contact.

Conductors and insulators

metal

Insulators do not allow heat to move through them easily. plastic Double-glazed window

air

air space

cork

Conductors allow heat to move through them easily.

Convection

gas particles

liquid particles

convection currents

This is the transfer of heat in liquids and gases.

Heat is transferred by the movement of currents.

Greenhouse

Radiation

solar radiation

radiation emitted by plants

This is the transfer of heat by electromagnetic waves.

No contact is necessary between the source and the heated substance.

ADAPTATION OF PLANTS ACCORDING

TO THE TEMPARATURES

The Desert :The desert is very dry and often hot. Annual rainfall averages less than 10 inches per year, and comes all at the same time. The rest of the year is very dry. There is a lot of direct sunlight shining on the plants. The soil is often sandy or rocky and unable to hold much water. Winds are often strong, and dry out plants. Plants are exposed to extreme temperatures and drought conditions. Plants must cope with extensive water loss.

Desert Plant Adaptations :•Some plants, called succulents, store water in their stems or leaves;•Some plants have no leaves or small seasonal leaves that only grow after it rains. The lack of leaves helps reduce water loss during photosynthesis. Leafless plants conduct photosynthesis in their green stems.•Long root systems spread out wide or go deep into the ground to absorb water;•Some plants have a short life cycle, germinating in response to rain, growing, flowering, and dying within one year. •Leaves with hair help shade the plant, reducing water loss. Other plants have leaves that turn throughout the day to expose a minimum surface area to the heat.•Spines to discourage animals from eating plants for water;•Waxy coating on stems and leaves help reduce water loss.•Flowers that open at night lure pollinators who are more likely to be active during the cooler night.Slower growing requires less energy.  The plants don't have to make as much food and therefore do not lose as much water.

This cactus displays several desert adaptations: it has spines rather than leaves and it stores water in its stem.

This cactus displays light-colored hair that helps shade the plant.

This plant has a waxy coating on its leaves.

•

The Temperate Grasslands :The temperate grasslands, also called prairie, feature hot summers and cold winters. Rainfall is uncertain and drought is common. The temperate grasslands usually receive about 10 to 30 inches of precipitation per year. The soil is extremely rich in organic material due to the fact that the above-ground portions of grasses die off annually, enriching the soil. The area is well-suited to agriculture, and few original prairies survive today. Temperate Grassland (Prairie) Plant Adaptations :•During a fire, while above-ground portions of grasses may perish, the root portions survive to sprout again•Some prairie trees have thick bark to resist fire•Prairie shrubs readily resprout after fire•Roots of prairie grasses extend deep into the ground to absorb as much moisture as they can•Extensive root systems prevent grazing animals from pulling roots out of the ground•Prairie grasses have narrow leaves which lose less water than broad leaves•Grasses grow from near their base, not from tip, thus are not permanently damaged from grazing animals or fire•Many grasses take advantage of exposed, windy conditions and are wind pollinated•Soft stems enable prairie grasses to bend in the wind

Soft stems enable prairie grasses to bend in the wind.  Narrow leaves minimize water loss.

Many grasses are wind pollinated and are well-suited to the exposed, windy conditions of the grasslands.

The Tropical Rainforest :The tropical rainforest is hot and it rains a lot, about 80 to 180 inches per year. This abundance of water can cause problems such as promoting the growth of bacteria and fungi which could be harmful to plants. Heavy rainfall also increases the risk of flooding, soil erosion, and rapid leaching of nutrients from the soil (leaching occurs when the minerals and organic nutrients of the soil are "washed" out of the soil by rainfall as the water soaks into the ground). Plants grow rapidly and quickly use up any organic material left from decomposing plants and animals. This results is a soil that is poor. The tropical rainforest is very thick, and not much sunlight is able to penetrate to the forest floor. However, the plants at the top of the rainforest in the canopy, must be able to survive 12 hours of intense sunlight every day of the year. There is a great amount of diversity in plant species in the tropical rainforest.

Tropical Rainforest Plant Adaptations :•Drip tips and waxy surfaces allow water to run off, to discourage growth of bacteria and fungi•Buttresses and prop and stilt roots help hold up plants in the shallow soil•Some plants climb on others to reach the sunlight•Flowers on the forest floor are designed to lure animal pollinators since there is relatively no wind on the forest floor to aid in pollination•Smooth bark and smooth or waxy flowers speed the run off of water•Plants have shallow roots to help capture nutrients from the top level of soil.•Many bromeliads are epiphytes (plants that live on other plants); instead of collecting water with roots they collect rainwater into a central reservoir from which they absorb the water through hairs on their leaves•Epiphytic orchids have aerial roots that cling to the host plant, absorb minerals, and absorb water from the atmosphere

Drip-tips on leaves help shed excess water.

Prop roots help support plants in the shallow soil.

Some plants collect rainwater into a central reservoir.

The Temperate Rain Forest :The temperate rain forest features minimal seasonal fluctuation of temperature .The winters are mild and the summers cool. The temperate rain forest receives a lot of precipitation, about 80 to 152 inches per year. Condensation from coastal fogs also add to the dampness. The soil is poor in nutrients. Large evergreen trees, some reaching 300 feet in height, are the dominant plant species.Temperate Rain Forest Plant Adaptations :•Epiphytes such as mosses and ferns grow atop other plants to reach light.•Cool temperatures lead to slow decomposition but seedlings grow on "nurse logs" to take advantage of the nutrients from the decomposing fallen logs.•Trees can grow very tall due to amount of precipitation.

Epiphytes live on other plants to reach the sunlight.

Trees can grow very tall in this very moist environment.

The Temperate Deciduous Forest :There are four distinct seasons in the temperate deciduous forest: spring, summer, autumn, and winter. The temperature varies from hot in the summer to below freezing in the winter. Rain is plentiful, about 30 to 50 inches per year. The temperate deciduous forest is made up of layers of plants; the number of layers depends upon factors such as climate, soil, and the age of the forest. The tallest trees make up the forest canopy which can be 100 feet or more above the ground. Beneath the canopy, the understory contains smaller trees and young trees. These understory trees are more shade tolerant than canopy trees. Below the understory is a shrub layer. Carpeting the forest floor is the herb layer made up of wildflowers, mosses,and ferns. Fallen leaves, twigs, and dried plants cover the ground, decompose, and help add nutrients to the topsoil.

Temperate Deciduous Forest Plant Adaptations :•Wildflowers grow on forest floor early in the spring before trees leaf-out and shade the forest floor •Many trees are deciduous (they drop their leaves in the autumn, and grow new ones in spring). Most deciduous trees have thin, broad, light-weight leaves that can capture a lot of sunlight to make a lot of food for the tree in warm weather; when the weather gets cooler, the broad leaves cause too much water loss and can be weighed down by too much snow, so the tree drops its leaves. New ones will grow in the spring. •Trees have thick bark to protect against cold winters.

Broad leaves can capture a lot of sunlight for a tree.

Many trees have thick bark to protect against the cold winters in the temperate deciduous forest.

In the autumn, deciduous trees drop their leaves to minimize water loss.

The Taiga :Also know as boreal forests, the taiga is dominated by conifers (cone-bearing plants), most of which are evergreen (bear leaves thorughout the year). The taiga has cold winters and warm summers. Some parts of the taiga have a permanently frozen sublayer of soil called permafrost. Drainage is poor due to the permafrost or due to layers of rock just below the soil surface, and together with the ground carved out by receding glaciers, lead to the development of lakes, swamps, and bogs. The taiga receives about 20 inches of precipitation per year. The soil is acidic and mineral-poor. It is covered by a deep layer of partially-decomposed conifer needles.Taiga Plant Adaptations :•Many trees are evergreen so that plants can photosynthesize right away when temperatures rise •Many trees have needle-like leaves which shape loses less water and sheds snow more easily than broad leaves •Waxy coating on needles prevent evaporation•Needles are dark in color allowing more solar heat to be absorbed•Many trees have branches that droop downward to help shed excess snow to keep the branches from breaking

Needle-like leaves help reduce water loss and aids in the shedding of snow.

The shape of many conifer trees helps shed heavy snow to save branches from breaking.

The Tundra :The tundra is cold year-round—it has short cool summers and long, severe winters. The tundra has a permanently frozen sublayer of soil called permafrost. Drainage is poor due to the permafrost and because of the cold, evaporation is slow. The tundra receives little precipitation, about 4 to 10 inches per year, and what it does receive is usually in the form of snow or ice. It has long days during the growing season, sometimes with 24 hours of daylight, and long nights during the winter. There is little diversity of species. Plant life is dominated by mosses, grasses, and sedges. Tundra Plant Adaptations :•Tundra plants are small (usually less than 12 inches tall) and low-growing due to lack of nutrients, because being close to the ground helps keep the plants from freezing, and because the roots cannot penetrate the permafrost.•Plants are dark in color—some are even red—this helps them absorb solar heat.•Some plants are covered with hair which helps keep them warm.•Some plants grow in clumps to protect one another from the wind and cold.•Some plants have dish-like flowers that follow the sun, focusing more solar heat on the center of the flower, helping the plant stay warm.

This plant grows in a clump to help conserve

heat.

These tundra plants are low-growing.

Plant Adaptations in Water :•Underwater leaves and stems are flexible to move with water currents•Some plants have air spaces in their stems to help hold the plant up in the water•Submerged plants lack strong water transport system (in stems); instead water, nutrients, and dissolved gases are absorbed through the leaves directly from the water.•Roots and root hairs reduced or absent; roots only needed for anchorage, not for absorption of nutrients and water•Some plants have leaves that float atop the water, exposing themselves to the sunlight•In floating plants chlorophyll is restricted to upper surface of leaves (part that the sunlight will hit) and the upper surface is waxy to repel water•Some plants produce seeds that can float

In floating plants, chlorophyll is restricted to the upper surface.  Note the green colour on the top of the leaves and the reddish underside of the overturned leaf.

Aquatic plants must be flexible to withstand the pressures of moving water.

ADAPTATION IN ANIMALS ACCORDING TO THE

TEMPRATURE

`

Adaptations

Tropism… is the response of an organism toward or away from a

stimulus.

Remember:Stimulus is something that produce a response of an

organism.

CamouflageAn appearance that makes something look like its surrounding; could be its shape or color.

Example:Color Camouflage

-ChameleonShape Camouflage

-Stick bug

• An adaptation in which the animal is protected against predators by its resemblance to another animal. It looks like, but it’s not!!

Mimicry

Mimicry

To its colour

To its shape

Insulation – refers to a material that does not conduct heat well.

Examples:Birds – feathersWhales – blubberSome mammals - fur

Adaptations to colder climates

Animals must be able to get rid of excess heat.In desserts we can found:

Fennec – have huge ears that provide a large surface area from which heat can escape.Camels – Their humps are made of fat, so they can live off this stored fat when food is scarce.

*Other animals dig themselves to escape the heat of summer or the cold winter in the dessert.

Adaptations to Hot Climates

The Fennec

Animals can respond by instinct or with the help of a learned behavior.

An instinct… is an inherited behavior that is done automatically.

An instinct can not be learned.Examples: Feed, built nests, attract mates, defend themselves.

Behaviors and Migration

Everything that we done because we learned it, observing or assisted by someone else.

Examples :In humans In other animals:

Share HuntingBe organizeCooperate

Learned behavior

Means to move from one place to another.Reasons:

Availability of foodChanges in climateMating Give birth

Migration

Most birds and some insects migrate to warm climates during the fall season.

At this time of the year the temperature drops and the food available is reduced.

Migration

THE END