PHY2 LAB ACTIVITY #2B
GROUP NUMBER: Group 3
SECTION: ECE - 1B
NAME OF MEMBERS:
● Mission, Jaycee Emmanuel
● Palad, Vhon Jervie S.
● San Pascual, Mikee S.
● Sta. Ana, Arlan Gabriel I.
● Templanza, Russel C.
● Yu, Janela S.
DIRECTION
Search for YouTube videos on experiments conducted about the SECOND LAW OF
THERMODYNAMICS
Provide the following:
1. State the Second Law of Thermodynamics:
In simple terms, The Second Law of Thermodynamics states that first, heat
always flows from a high-temperature body to a low-temperature body. This is
called an irreversible process. However, there cannot be a circumstance where
heat is transferred from colder objects to hotter objects.
Furthermore, it also introduces a new property called entropy, S, which is
an extensive property of a system. In an irreversible process, the combined
entropy of the system and the environment must always increase. The final entropy
must be greater than the initial entropy for an irreversible process. The change in
entropy delta S is equal to the heat transfer delta Q divided by the temperature T.
(ΔS = ΔQ / T)
2. Video title and link:
Title: Second Law of Thermodynamics Experiment
Link: https://www.youtube.com/watch?v=P4pl_bdS5FA
3. State the objective of the Experiment:
● To recognize what will happen to the balloons if they are heated.
● To understand why the first balloon (filled with air) exploded and the second
balloon (filled with water) did not.
● To know the property of water that enabled it to absorb heat without the
balloon breaking.
● To learn what is entropy and how heat flows inside a system.
● To comprehend the concept of the Second Law of Thermodynamics.
4. Brief description of the nature of the experiment:
The Balloon in Candle is under the concept of the Second Law of
Thermodynamics which is easy to explain. Placing the balloon at the flame of the
candle is a mechanism that the experiment shall undergo. In this experiment, there
are two objects to be taken into consideration, the candle, and the balloon. Also,
the most important factor in this experiment is the water that will be placed inside
the balloon. At the end of the experiment, the expected result would be the balloon
filled with water will not pop, unlike the balloon without water.
5. List of materials used in the experiment:
● Balloons
● Water
● Candle
● Matchstick
● Extra Towel
6. Detailed procedure of the experiment
● Inflate the 1st Balloon and tie it closed.
● Place ¼ cup of water then Inflate the 2nd Balloon and tie it closed.
● Light a candle with a match.
● Hold the 1st balloon 30–50 cm over the top of the flame and slowly move
the balloon closer and closer to the flame until it pops
● As before, Hold the 2nd balloon and slowly lower the balloon over the
candle flame. The balloon will not pop. You can let the flame touch the
balloon and it will still not pop.
7. Observations made on the conduct of the experiment:
When air is blown to the balloon it expands. The first balloon popped.
When the balloon is directed at the flame in the candle, it pops instantaneously.
When the balloon with water is directed at the flame in the candle, the part of the rubber
balloon that was exposed to the flame only darkened. The balloon with water did not
pop.
8. Result / Outcome and Conclusion obtained from the performed experiment:
The first Balloon:
The heat from the flame heats the air within the balloon, causing it to expand. Without
water, the balloon's rubber heats up to the point that it can no longer withstand the
pressure of the air inside the balloon making it pop.
The second balloon:
Because water is a good conductor of heat, when the water inside the balloon is exposed
to the flame, the water absorbs the majority of the heat. Because the balloon does not
become heated, the rubber does not weaken and the balloon does not shatter.
While the water balloon survives the flame, the water inside the balloon will start to cycle
around and around due to convection. As the warmer water rises, the cooler water
beneath it moves in to take its place. When the warmer water reaches the top of the
balloon, it is no longer in contact with the flame, and it contracts as it cools. The water
becomes denser as a result of the contraction, and it sinks again. Meanwhile, the water
near the candle flame heats up, expands, and rises. As a continuous circular motion of
water within the balloon, the process continues to repeat itself.
In conclusion, when the balloon is exposed on the flame, energy is transferred in the form
of heat “Q”
Heat flow generate entropy, Q = TS
—---------------------------------------------------------------------------------------------------------
The water will continue to absorb the heat from the flame.
So, how long could you run this? Well, it really depends on how much water you have in the
balloon as well as the quality of the rubber balloon itself.
whilst the water balloon survives the flame, the water inside the balloon will start to cycle around
and around due to convection.
Convection is the movement of either gasses or liquids due to uneven heating causing density
changes that drive movement. How does this convection work in the balloon then?
– Warmer water rises due to the water expanding and becoming less dense than the
surrounding colder water.
– As the warmer water rises, the surrounding colder water moves underneath to replace the
warm water.
– Once the warmer water reaches the top of the balloon it is away from the flame so it contracts
as it cools down. This contraction makes this water denser and so this water moves down
again.
– In the meantime the water that had moved near the candle flame also heats up and expands
and rises. The process keeps repeating as a continual circular motion of water within the
balloon.
9. What significance does the video experiment hold on the First Law of
Thermodynamics?
The "Second Law of Thermodynamics" was significantly proven with the help of
this experiment. Generally, this experiment had demonstrated not just one ideology of
the Law, but two.
First is the concept of the Second Law itself, which states that heat can only be
transferred from the system with a higher temperature to the system with a lower
temperature. In this case, the candle with a lit fire is the system with a higher temperature,
and the balloons are the system with a lower temperature. In the first balloon, the heat
was transferred from the candle into the balloon filled with air, and it caused the balloon
to pop because air is not a good conductor of heat, and it also expands rapidly when in
contact with heat. However, on the second balloon, the heat was not transferred to the
balloon itself but the water inside of it because water is known as a good conductor of
heat. Thus, due to the process of convection, the balloon did not pop.
The second is the concept of irreversibility and entropy which is also introduced to
us by the Second Law. In thermodynamics, irreversible processes are the ones that
cannot be undone or revised. The system that undergoes an irreversible process can not
be returned from its original state after the process happened. On the other hand, entropy
is the amount of thermal energy that can not do beneficial work. It is said to increase as
the temperature increases. According to the Law, in an irreversible process, entropy
should always be constant or increasing but never be decreasing. In this experiment, the
process that took over is irreversible - the objects, after achieving thermal equilibrium, will
not return from their initial temperatures. Furthermore, because there was a heat flow that
happened during the process, the temperature increased, and therefore, an increase in
the entropy also occurred.
In conclusion, the balloon in a candle experiment is considered one of the proofs
in discussing the ideology of the Second Law of Thermodynamics.
10. Literature to support that your chosen video experiment verifies the First
Law of Thermodynamics
● The gist of the Literature:
According to Benson (n.d.), some processes follow the First Law of
Thermodynamics but never really occurred in nature. Taken into example was the
process of having a hot object in contact with a cold object. During this process, heat
transfers from the hot object to the cold object but never vice versa. Because even if this
process (cold to hot) did not violate the First Law of Thermodynamics, there are no such
systems in the universe that presents a similar behavior. Thus, the Second Law of
Thermodynamics was formed - in the amendment to the First Law of Thermodynamics which focuses on the direction of heat flow in a system. In addition, Benson also said that
“The second law states that if the physical process is irreversible, the entropy of the
system and the environment must increase; the final entropy must be greater than the
initial entropy. An example of an irreversible process is the process where a hot object is
put in contact with a cold object. Eventually, they both achieve the same equilibrium
temperature. If we then separate the objects they do not naturally return to their original
(different) temperatures. The process of bringing them to the same temperature is
irreversible”.
● Link:
Benson T., (n.d.) Second Law of Thermodynamics [Online]. Retrieved April 6, 2022,
from https://www.grc.nasa.gov/www/k-12/VirtualAero/BottleRocket/airplane/thermo2