This document discusses heat as a form of energy. It defines heat as the transfer of energy between objects due to a temperature difference. The document then describes an experiment conducted to determine the specific heat capacity of aluminum. In the experiment, an aluminum cylinder was heated by an immersion heater for 600 seconds. The temperature increase of the cylinder was recorded. Using the temperature change and energy input, the specific heat capacity of aluminum was calculated. While the calculated value did not exactly match the known value, it was in the correct order of magnitude. The document then discusses applications of heat as an energy, including solar panels and geothermal heat pumps.
2. • What is heat as an energy ??
• All matter contains heat energy. Heat energy is
the result of the movement of tiny particles called
atoms, molecules or ions in solids, liquids and
gases. Heat energy can be transferred from one
object to another. The transfer or flow due to the
difference in temperature between the two
objects is called heat.
3. Heat always moves from a warmer place to a cooler place.
Hot objects in a cooler room will cool to room temperature.
Cold objects in a warmer room will heat up to room temperature.
Heat is a form of energy which passes from a body at higher temperature to a
body at a lower temperature.
4. Objective
the main objective of this experiment is to study of determining the specific
heat capacity of aluminium.
Use the equation to find the specific heat capacity of aluminium in the end
of experiment.
Learn about the heat as an energy.
Study of determining the specific heat capacity of aluminium.
Find the specific heat capacity of aluminium in the end of
experiment.
5. Theory Of Heat As An Energy
• J.P Joule did several experiments to establish our present view about the heat. He
also established a relationship between mechanical work and heat energy in the
form WʠH/ W=JH
Modern microscopic view:
In case of solids, the molecules vibrate about their mean positions, but in liquid and
gasses, the molecules travel from here and there. According to the modern
microscopic view, the thermal kinetic energy increases with an increase in
temperature.
e.g- a pot of water placed on a stove burner. K.E on the pot increase,causing its
transfer a little bit its K.E to water causing water to collide each other extremely.
Then, temperature of the pot and water is rise.
Object heated heat increase = Translational K.E increase, rotational & vibrational
K.E increase
Total energy is the sum of the 3 K.E
6. Specific heat capacity
• The experimental determination of the specific heat of a metal by the method of mixtures
consists in dropping a known mass of the metal at a known high temperature into a known
mass of water at a known high temperature into a known low temperature. The heat absorbed
by the water, calorimeter, and stirrer is equal to the heat lost by the metal. Its competed from
the following equation:
𝑀 𝐶 ( T - 𝑇2 ) = (𝑐 𝑤 𝑚 𝑤 + 𝑐 𝑐𝑎𝑙 𝑚 𝑐𝑎𝑙)(𝑇2 − 𝑇1)
M-mass of metals(g) 𝑇1- initial temperature.
c-specific heat of the metal (𝑐 𝑐𝑎𝑙 𝑚 𝑐𝑎𝑙)- water equivalance of the calorimeter and stirrer
T-temperature of the metal 𝑚 𝑤- mass of the cold water
𝑇2-equilibrium temperature
7. Specific heat Capacity, c
• The quantity of heat needed to increase the temperature of a mass 1 kg by 1˚C or
1 K.
• Can be calculated from the amount of heat supplied, Q to a mass, m of a substance
and the increase in temperature, ∆θ.
• 𝑐 =
𝑄
𝑚∆𝜃
• Where m = mass,
Q = heat supplied
θ = change in temperature.
• The unit of specific heat capacity is J kg-1 ˚C-1.
• Different substance are said to have different specific heat capacities.
8. Result :
Time (sec) Temperature (˚C)
0 14
60 17
120 19
180 21
240 23
300 25
360 28
420 32
480 35
540 38
600 45
9. Determine the specific heat capacity, c of
solid aluminium
Electric power of heater = 50 watt
Heating time = 600 seconds
Mass of aluminium cylinder = 1.0 kg
Initial temperature of the aluminium
cylinder
= 14 ˚C
Final temperature of the aluminium cylinder = 45 ˚C
Temperature rise = 45 – 14 = 31 ˚C
Electrical energy supplied by the heater = 50 x 600 = 30,000 J
Heat energy absorbed by the aluminium
cylinder
= mcθ
Heat supplied = Heat absorbed
30000 = 1.5(26)c
Specific heat capacity, c = 30000
1.0 × 31
= 30000
31
= 967.74 J/kg. ˚C
10. Discussion
• The actual value for the specific heat capacity of aluminium is 900
J/kg°C.
• The specific heat capacity of aluminium is a constant.
• The value of specific heat capacity of the aluminium, c determined in
the experiment is larger than the standard value because of :
Heat lost to the surrounding
Assume the heat supplied is absorbed by the aluminium
temperature still increases although the heater is switched off
11. Properties of Aluminium which has a
higher specific heat capacity :
• It takes a longer time to be heated.
• It does not lose heat easily.
• It is usually used as a heat insulator.
• It is a poor heat conductor.
12. • Heat is a form of energy which exists naturally and it is quite
important to all aspects of life. The statistic shows that nearly half of the
energy use in the UK is for heat. It is because the heat quickly changes into
different forms of energy like light, electricity and others. As a results, heat
is applied into our daily to improve the quality of lifestyle.
13. Application of heat as an energy
1. Solar panel
- comprise many, smaller units called photovoltaic cell
- cells linked together make up solar panel
- photovoltaic cell made up of two slices of semi-conducting material, usually silicon
- the cell are so light which are 20 times lighter than a sheet of office paper
- solar panel works by allowing photons, or particles of light to knock electrons free
from atoms and generating a flow of electricity
14.
15. 2. Geothermal Heat Pump
ground source heat pump, highly efficient renewable energy technology
is a natural source of power found below the surface of the earth
by transferring heat stored in the earth into the building during winter and transferring it
out of the building and back into ground during summer
there are four types of pumps which are three closed-loop systems and open-loop systems
17. Conclusion
• The actual value for the specific heat capacity of aluminium is 900 J/kg°C.
The calculated value does not match exactly but it is in the correct order of
magnitude. This is because not all of the heat from the immersion heater
will be heating up the aluminium block, some will be lost to the
surroundings. More energy has been transferred than is needed for the
block alone, as some is transferred to the surroundings. This causes the
calculated specific heat capacity to be higher than for one kilogram (kg) of
aluminium alone.However.in this experiment we assume that all the heat
supplied is absorbed by the aluminium block. Therefore, the specific heat
capacity of aluminium is constant which means it does not influence by
any factors.
18. Acknowledgment
First of all, our groups would also like to express us deep gratitude to Dr
Faridah Abd Razak for her valuable constructive a nice suggestions and advice
in keeping my progress on schedule.Our group also wish to thank for our
parents for giving us their support and encouragement throughout we study. I
heartily thank you to my group members without them the assignment cannot
be completed for their effort and cooperation which are Dayang, Syaffica,
Zufira, Thiveyaa, Suganthi and Ong Khai Heo.Last but not least, we would like
to express our gratitude to our friends for giving support and willingness to
spend more time with us during doing this assignment.
19. References
• https://www.livescience.com/41995-how-do-solar-panels-work ( 6/12/17 by Michael
Dhar, Live Science Contributor)
• https://www.saveonenergy.com/how-geothermal-energy-works/ (2018 by Save on
Energy)
• https://www.youtube.com./watch?v=huKu6Euuu_l
• https://www.bbc.com/bitesize/guides/zcpwrwx/revision/6
• Lim Peng Chew, L. C. (2012). NEXUS SPM A+ Physics. In L. C. Lim Peng Chew, NEXUS SPM
A= Physics (pp.191-192). Lot 508, Jalan Perusahaan 3, Bandar Baru Sungai Buloh, 47000
Selangor.:Sasbadi Sdn.Bhd.