Physics 137

Is the ozone layer harmful to life on Earth?

(Layer between the troposphere and stratosphere) Ozone layer is good and blocks harmful uv radiation from the sun

Anthropogenic

(human caused) environmental change

10^17 W

1000000000000000000 Watts

Oxidation

A chemical change in which a substance combines with oxygen, as when iron oxidizes, forming rust

Gross Domestic Product (GDP)

A measurement of the total goods and services produced within a country. (economic activity)

What is meant by forces in physics?

A push or a pull Examples: Electromagnetic forces-- light, radio waves, friction, chemical reactions, magnetism, Gravity Nuclear Force

Earth's agents of change

Astrophysical, geological, chemical, and biological

Find the energy-consumption rate for five electrical devices you use every day. This value--in Watts--is generally listed somewhere on the device or its power adapter, if it has one.

Blow Dryer - 1200 Watts Refrigerator - 600 Watts Electric oven - 3,000 Watts iPhone- 5.45 Watts TV- 200 Watts

Photosynthesis

Conversion of light energy from the sun into chemical energy.

Figure 2.3 suggests that global average per capita energy consumption has risen not quite fourfold since the year 1800. You might find that change surprisingly small, given the huge number of new energy-dependent technologies developed since 1800. What factors might account for this apparent discrepancy?

This discrepancy exists because not all nations have developed in relation to technology and energy consumption since the year 1800. These regions of high energy consumption mostly exist in first and second world countries. Majority of global citizens do not own a car, contrary to American living.

Why does carbon dioxide warm the earth?

Traps suns warmth

Why is it harder to walk uphill than on level ground?

Have to increase potential energy as increase elevation

Anthropogenic

Human-induced changes on the natural environment

What is the most significant change life has made on Earth's environment?

Introduction of photosynthesis and oxygen to life's atmosphere

Timeline of Earth's history

Line upon line, over a long time, effect of photosynthesis on life forms and the atmosphere

A newspaper article claims that a new power plant "produces 50 megawatts of energy each hour, enough to power 30,000 homes." Criticize the statement.

Megawatts are not energy units. Megawatts measure power, which is the rate of energy use.

Snowball Earth

The hypothesis that glaciers covered the planet's land masses from pole to pole 750 to 570 million years ago.

thermal energy

anything with heat and friction

Efficiency

The percentage of the input energy (or power) available as output energy (or power) Efficiency= useful output energy/total input energy x 100% Efficiency = useful output power/total input power x 100%

Graph tips

The x-axis is typically the dependent variable and the y-axis is the independent variable

practice to find useful power

efficiency/100 (total power) = useful power

end use energy

energy actually consumed in each sector

difference between power and energy Power = Energy/Time

energy is attached to fuels and power is how fast that power is being used

kinetic energy

energy of motion

Difference between nuclear power and fusion

nuclear power does nuclear fission where radioactive isotope goes into decay-- breaking down fusion is putting together like two hydrogens and boom

fossil fuels

practically stored sunlight energy

potential energy

stored energy

Matter

the physical "stuff" that makes up the universe

Power

the rate at which work is done

Energy

universal "stuff" associated with motion, heat, and the fundamental forces of nature

unit conversion video

watch now

endowment of the earth

what qualities have been given based off the sun (cool cuz symbolic of what we have been given by the son)

power output

The amount of work performed per unit of time measured in Watts (W).

energy intensity

The energy use per unit of gross domestic product

If the earth's temperatures have varied in the past, why is it a concern if the Earth's temperature increases today?

Different life forms were adapted to different temperatures and we are adapted to the temperature now The rate of change doesnt allow to adapt in time Changes are driven and arent natural cycle of the earth

Whats the difference between energy flow and fuel?

Energy flows are streams of energy that arrive at or near Earth's surface at a more or less steady rate, bringing energy whether its needed or not. Fuels, in contrast, represent energy that is stored in one form or another - most commonly in the chemical bonds of molecules or in atomic nuclei. Fuel energy usually remains stored energy until a deliberate act liberates it.

geothermic energy

Energy generated from the heat produced beneath the earth's mantle; usually in reference to the use of subterranean steam to drive engines that produce electricity

primary energy

Energy of fuels consumed to supply various sectors

What is the primary ingredient to our atmosphere?

Nitrogen

feedback loop

Occurs when an output of matter, energy, or information is fed back into the system as an input and leads to changes in that system. (fire doesnt have feedback mechanism whereas heater can modify based on the sensor)

Whats a k-W-hr?

One of many units for energy. What you pay for on your electric bill 1 k-W-hr is the energy used to raise an apple up and down a distance of 1 m each second for one hour Unit of energy

Whats a Watt?

One of many units of power: Joules/second The rate at which energy is used or delivered 1 Watt is the used to raise an apple up and down kW=power

Why did the atmospheric oxygen content not rise immediately after "invented" photosynthesis?

Oxidization

The atmosphere

Troposphere, stratosphere, mesosphere, thermosphere, exosphere

When the earth was in a snowball state, it would have reflected nearly all the incoming solar energy. How was our planet able to warm from the snowball state?

Volcanoes (powered by geothermal energy) continued to spew Carbon Dioxide from Earth's interior and atmospheric Carbon Dioxide increased rapidly, (increases green house effect) with its insulating effect of the atmosphere and Earth's surface temperature. Eventually equatorial ice melted, exposing dark ocean water to the strong tropical sunlight, and the warming rate increased.

feedback mechanism of earth before humans

Volcanoes and rain

Although the growth rate of the global human population peaked in the 1960s, 1988 was the year when the world added the greatest number of people. Why the difference?

While the growth rate of 2% in the 1960s was the peak, the number of people in the world continues to grow. Therefore, in 1988 there were more people in the world, so the ratio of the growth rate might not have been as high as the 1960s but the number of people being more itself was large because that is the trend of the population in this time period.

geothermal

came from Earth's internal heat (chemotrophs)