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Week 7 Science: Heat Transfer (thermodynamics)

Last updated over 5 years ago
9 questions
Apollo 11 was the spaceflight that first landed humans on the Moon. Commander Neil Armstrong and lunar module pilot Buzz Aldrin formed the American crew that landed the Apollo Lunar Module Eagle on July 20, 1969, at 20:17. Armstrong became the first person to step onto the lunar surface six hours 39 minutes later on July 21 at 02:56; Aldrin joined him 19 minutes later. They spent about two and a quarter hours together outside the spacecraft, and collected 47.5 pounds (21.5 kg) of lunar material to bring back to Earth. Command module pilot Michael Collins flew the command module Columbia alone in lunar orbit while they were on the Moon's surface. Armstrong and Aldrin spent 21 hours 31 minutes on the lunar surface at a site they named Tranquility Basebefore lifting off to rejoin Columbia in lunar orbit.

Apollo 11 was launched by a Saturn V rocket from Kennedy Space Center on Merritt Island, Florida, on July 16 at 13:32 UTC, and was the fifth crewed mission of NASA's Apollo program. The Apollo spacecraft had three parts: a command module (CM) with a cabin for the three astronauts, and the only part that returned to Earth; a service module (SM), which supported the command module with propulsion, electrical power, oxygen, and water; and a lunar module (LM) that had two stages – a descent stage for landing on the Moon, and an ascent stage to place the astronauts back into lunar orbit.

After being sent to the Moon by the Saturn V's third stage, the astronauts separated the spacecraft from it and traveled for three days until they entered lunar orbit. Armstrong and Aldrin then moved into Eagle and landed in the Sea of Tranquility. The astronauts used Eagle's ascent stage to lift off from the lunar surface and rejoin Collins in the command module. They jettisoned Eagle before they performed the maneuvers that propelled the ship out of the last of its 30 lunar orbits on a trajectory back to Earth. They returned to Earth and splashed down in the Pacific Ocean on July 24 after more than eight days in space.

Armstrong's first step onto the lunar surface was broadcast on live TV to a worldwide audience. He described the event as "one small step for [a] man, one giant leap for mankind."Apollo 11 effectively ended the Space Race and fulfilled a national goal proposed in 1961 by President John F. Kennedy: "before this decade is out, of landing a man on the Moon and returning him safely to the Earth."

See the NASA video below
Now let's talk about Heat Transfer (video below) and a bit about Thermodynamics (text below):

Thermodynamics

As you know, energy cannot be created or destroyed. So what happens to energy when an object is heated or cooled? Let’s think about what happens when you place your hands around a mug of hot chocolate. Is heat energy released to the surroundings (your hands), or is it absorbed by the hot chocolate? Your hands start to warm up from holding the hot chocolate, therefore the heat energy must be released by the hot chocolate and absorbed by your hands. This physical reaction is called exothermic.
Thermodynamics is the science that deals with the relationship between heat, pressure, density, and temperature in a substance. Thermodynamics specifically focuses largely on how the transfer of heat is related to various energy changes within a physical system. Those changes in heat usually result in work being done by the system. The changes are guided by the laws of thermodynamics.
An exothermic reaction can be a chemical or a physical object that releases heat energy to its surroundings. The opposite of this reaction is endothermic. An endothermic reaction absorbs heat from its surroundings. Figure 1 shows an example of exothermic and endothermic phenomena you are probably familiar with.
Heat and temperature are not the same thing. Heat is a form of energy; it is measured in calories or joules. Temperature is a measure of the average kinetic energy of the particles in a substance; it is measured in kelvins or degrees.
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1

Thermodynamics is the relationship between ________ in a substance.

1

When a cold stick of butter is left out on the kitchen counter ___________.

1

Explain how thermodynamics is observed when a cold spoon is placed in pot of boiling water.

1

What happens if a metal object heated to 130° Celsius is placed in a container of water that is 24° Celsius?

1

Which of the following describes a closed system?

1

A cup of hot coffee is placed on the counter in a room that is about 22° Celsius. How would you describe the energy of the cup of coffee after two hours?

1

Insulator

1

What does thermodynamics say about the flow of energy between two objects of different temperatures?

Try this at Home! Make SUN TEA!

Use the sun's energy to brew tea.

1. Put 4 to 8 tea bags into a santitized 2 quart or gallon glass container (use fewer teabags for a smaller container: 4 teabags for a 2 quart container, 8 tea bags for a gallon container).
Always use a glass container or BPA-free container. Do not use single use plastic water bottle.
2. Fill with water and cap.
3. Place outside where the sunlight can strike the container for about 3 to 4 hours. Move the container if necessary to keep it in the sun. Leaving tea out for too long, brewing in plastic, or not cleaning your sun tea container can cause bacteria to grow into ropey strands or white spots, or make it thick or syrupy consistency; if it does, discard it.
4. When the tea has reached its desired strength, remove from sun and put it in the refrigerator. You may or may not want to remove the tea bags at this point. I usually don't. The tea will probably taste more mellow than what you are used to from using boiling water. The slow steeping has a way of bringing out a slightly different flavor from the tea. Also, because you didn't use boiling water, you should refrigerate the tea and drink it up pretty quickly - a day or two. It will not keep as well as iced tea made from boiling water. I usually make sun tea with various kids of tea, but black tea and green tea are my favorites.
5. Pour the tea into a clear glass. Take a close look to make sure the tea does not have any bacteria as explained above. Add ice and sometimes sweetener or sprigs of mint and enjoy.


1

What kind of heat (energy) transfer is making the sun tea brew? (check all that apply)