Group 7

Document Sample
Group 7 Powered By Docstoc
In 1997, Reliance Industries opened the
Jamnagar Oil Refinery – The Largest
Grassroots refinery in the world. Once an arid
region, Jamnagar is all set to become oil hub
of the world.
Aim: To examine the foods being consumed by the villagers in
terms of the amount of energy they gained from it and compare
this to the kind and hours of work they put in every day, thus
deciding whether the food they were eating provided them with
enough energy.

Hypothesis: The food which exhibits the greatest change in
temperature provides the greatest amount of heat energy, and
hence allows the most work to be done. Thus we think that the
energy from the food consumed by the labourers will be
significantly higher will be significantly higher than consumed by
the landowners.
Q1] what type of food do you eat?
Q2] Can we have samples?
Q3] How often in a day do you eat?
Q4] What kind of work do you do?
Q5] How many hours a day do you work for?
Q6] Do you get your food from the market or is it
 grown in your farm?

•Weigh the given food item, in this case potato, and record the
initial mass
•Set up the apparatus like in the diagram below.
•Heat the potato for 1 minute, recording the temperature of the
water in the test tube every 5 seconds. Ensure that the potato
does not burn out completely.
•Repeat the above steps with all the given food items.

Mass of Bajra- 2.65 grams
Mass of water 7.12 grams
Final Mass of Bajra – 2.33 grams
Therefore, MC Δt = 7.12 12.5 4.2 J = 373.8
373.8/4.2 = 89 calories

Initial Mass – 3.8 grams
Mass of water – 3.2 grams
Final Mass of Potato – 2.69 grams
Therefore, MCΔT =2.69 x 4.2 x 11.9 = 134.446/4.2
= 31.90 cal
Egg Plant:

Initial mass – 11.19
Mass of water – 5.06
Final mass of eggplant – 7.65
Therefore, mCΔT = 5.06 x 4.2 x 5.7 = 121/4.2 = 28.8
= 28.8 cal
According to our above results, the following is the ranking order for calories from
maximum to least – 1) Bajra 2) Potato 3) Egg plant.

This shows us that people eating Bajra obtain more energy. This energy content is
directly related to the amount of hydrocarbons present in these various food products
because it is these chemicals which get burned to release the heat energy raising the
temperature of the water. This means that Bajra is the most energy efficient food.
However, these values when compared to the literature values were very different from
the ones that we obtained. For the potato and the Bajra and potato, the lab values are
less than the literature values , this is because in the lab while the experiment was being
conducted, a calorimeter was not available to us and furthermore there was no
insulating material that could be used to prevent heat loss. Thus because of the very
large heat loss taking place to the surroundings, we have observed theses results. On the
other hand, the value for the egg plant is a little higher than the literature values
observed and this may have been due to the heat energy from the Bunsen burner
reaching the water and heating it as well, in addition to the heat energy of burning the
egg plant.
Aim: We examined the fuels being used for many purposes in
the running of the household (mainly cooking) to see how
energy efficient they are. Simultaneously, we examined
alternative options available on the market, and analyzed
whether the alternatives were more effective fuels than the
actual fuels being used.

Hypothesis: From the free availability of cow dung and the
prior knowledge that cow dung was less polluting than the
other fuels used in the village, we felt that cow dung would be
the best fuel for the villagers to use. Besides being
environmentally friendly, cow dung has a high calorific value,
i.e., it releases large amounts of energy when burnt.
Q1] What fuels are used in this household?
Q2] What fuels are available in the market?
Q3] What is the cost of the fuel used and the other
  possible fuels that can be used?
Q4] What activities are the fuels used for?
Q5] Which fuel according to you is the best?
Place the spirit lamp without its lid in the centre of the top pan balance and note
down its mass. Fill the spirit lamp with kerosene and note down the mass of the
spirit lamp now, thereby deducing the mass of kerosene used in the experiment.
Place an empty glass beaker on the top pan balance and note down its mass. Fill
the glass beaker with 100 ml of water, which will be measured using a measuring
cylinder Note down the mass of the beaker now, thereby deducing the mass of
100 ml of water used in experiment
Place the beaker on the wire gauze on a tripod stand. Under the stand, upturn
another beaker and place the spirit lamp on it.
Place the bulb of a digital thermometer in the water and note down the initial
temperature of water. Light the spirit lamp now, and subsequently record the
temperature of water every 30 seconds for a time period of 4 minutes. The
temperature at the end of 4 minutes will be termed as the ‘final temperature’.
After 4 minutes, note down the mass of the spirit lamp, thereby deducing the
mass of kerosene used in the experiment. The same above method was
conducted using cow dung and wood.
Kerosene:                              Wood:

Mass of beaker: 99.66g                 Mass of beaker: 99.57g
Mass of beaker + water: 198.86g        Mass of beaker + water: 198.65g
Mass of kerosene used: 2.55g           Mass of wood used: 5.28g
Therefore Energy Output = 2.712 kJ/g   Therefore Energy Output = 0.413 kJ/g

Mass of beaker: 100.39g
Mass of beaker + water: 198.83g
Mass of gobar used: 3.01 g
Therefore Energy Output = 2.060 kJ/g
The energy released by kerosene was found to be 2.7 12 kJ/g, the energy released by
wood was found to be 0.413 kJ/g and the energy released by gobar (cow dung) was
2.060 kJ/g. From this, we can see that the values for kerosene and gobar were
significantly higher than that of wood. Therefore, come to the conclusion that kerosene
releases the most energy per gram, followed by gobar and then wood. These results
were obtained because kerosene is highly inflammable and is a hydrocarbon that is
easily combustible, whereas wood and cow dung are not as inflammable and hence do
not release as much heat. However, kerosene when burnt burns very strongly and
releases a huge amount of smoke as well as soot, which is harmful to both, the
environment and the human body. Moreover, taking the economic costs into
consideration, we see that Kerosene costs Rs.11 per litre, whereas cow dung and wood
are freely available, since a large percentage of the population owns cows due to
involvement in agricultural activities. Since gobar gives off quite a large amount of
energy, is freely available, and does not pollute the environment as significantly as
kerosene, we come to the conclusion that gobar is the best fuel from those given.
•During the whole experiment there was a large amount of heat lost to the
environment through conduction, convection.
•During the kerosene was burning a lot of soot was collected on the beaker.
•While burning the cow dung, kerosene was required for it to continue burning,
hence some of the heat was from the burning of the kerosene and not all of the
cow dung was burnt.
•The wind velocity was not constant during the whole experiment, this prevented
the flame from heating the water evenly, hence all the heat may not have been
•After the water was heated for the required time the kerosene continued burning
for sometime before the flame was extinguished, this could have led to the loss of
kerosene which was not used to heat the water and would have affected the
Aim: To investigate experimentally and find what would be the
best building material for the houses in the villages in
Jamnagar, in order to keep them cool and hence conserve
energy which is otherwise spent on keeping the temperature
in the houses lower.

Hypothesis: Out of the different materials most commonly
used by the villagers in Jamnagar to build their houses that is
clay, bricks, and bricks coated with cow dung, bricks coated
with cow dung followed by clay and bricks will be the best in
order to maintain a cooler environment within the house. This
is because the cow dung bricks will have a higher specific heat
capacity and hence for a given amount of heat, it would raise
the temperature of the house by only a minimal amount.
Q1] What materials do you use to build your houses?
Q2] Can we have samples?
Q3] What materials are available in the market that
 you can use?
Q4] Is cow dung used in plastering the walls?
Q5] How much did it cost you to build the house?
•Three pieces of the respective materials are taken and weighed with
the help of a weighing scale and the masses are recorded.
•The initial temperature of each of the three materials are taken, and
they are then put into an oven pre-heated to 50°C
•The three materials are subjected to the same amount of heat for a
period of 15 minutes.
•The materials are then taken out from the oven and their
temperatures are then recorded.
•The materials are allowed to cool and their temperatures are
recorded again after 5 minutes and 10 minutes respectively.
Hence, we can see that the difference between the temperatures of
the surroundings and inside is most for the house built with bricks and
cow dung, followed by clay and then only bricks. Hence, it can be
inferred that the house built with bricks covered with cow dung, will
be the coolest.





30                                                     Brick with gobar



     0   0.5   1   1.5   2   2.5   3   3.5   4   4.5
We see that after the materials are subjected to the same amount of
heat, they show different rises in temperature, with the rise in
temperature for the bricks with cow dung being the least, followed by
clay and then bricks. This means that the specific heat capacity of bricks
with cow dung is very high and hence for a lot of heat energy supplied it
shows only a small rise in temperature. This makes it one of the best
materials to be use for house building as on a hot day, it will absorb the
heat energy without allowing a large increase in temperature, and in
doing so keeps the house cooler. Clay which is the second best heat
absorber, would be a good choice for the building of roofs, as when
placed in a slanting manner, it traps moisture which absorbs heat,
further helping in keeping the house cool. Thus, our readings show that
bricks plastered with cow dung should be used for the walls of the
houses and the roofs should be made by the clay tiles
We have seen experimentally as well as through practical
readings that the temperature in the house built with bricks
and cow dung is cooler and the difference between the
surroundings and the house was 5.3 °C. Assuming that in the
lack of these cooling conditions materials, energy will have to
be spent to keep the house cool. Assuming that this cooling is
provided by 1 fan, used for around 16 hours a day, we can
calculate approximately how much energy is spent on these.
With the information that there are around 700 farmers in the
village, the total utilization would be 11,200 hours.

Using the information that a normal ceiling fan working at the
highest speed uses 85 watts, we can see that an approximate
of 950 kWh of energy can be saved per day.
• The oven was set to a pre-heated temperature. The actual temperature
  inside the oven could have been different from the one that was selected
  on the temperature knob.
• The digital thermometer had a slight delay, while reading the
  temperature and this could have been resulted in a lot of error as the
  materials were cooling down really fast.
• All the materials were not put inside the oven together and were not
  taken out together and this could have resulted in the heat given to the
  materials vary a little.
• The brick was not covered with the cow dung completely and thus the
  effect due to this might not have been entirely accurate.
According to the experiments conducted by us, we concluded that:

•The best fuel to be used is gobar (cow dung).

•The best material to build the wall should made of brick plastered with cow
dung and the roof of clay tiles.

•The best food for laborers is a combination of bajra rotis and potato.
Sagar Rupani Abhijeet Kaji Manasi Shah Isha Ambani Nishita Nigam Ishani
Shukla Shriyansh Maheshwari Shireen Qureishi Aditya Mehta Prajay Patel

                             GROUP 7

Shared By: