The Sun as a Source of Energy
Summer Research Program f
New Rochelle High School
August 2012
Subject: Astronomy
Grades Level: 11 & 12
Time required: 30
minutes for the hands on activity and 20 minutes for the Starry Night computer
exercise which is optional
Introduction:
In this hand’s on activity students will measure energy from the Sun. They will
use Starry Night High School to explore the nature of our daytime star. Upon
completion, students will have a better appreciation for the Sun as a star and
its influence over life on this planet.
SWBAT:
Key concepts:
·
The Sun is the
main source of energy in the solar system
·
The Sun’s
Energy comes from the fusion of the lightest element, hydrogen into
helium
·
The Sun will
continue to shine for another five billion years
Materials required
·
Several glass
jars (half liter or half quart size
·
Rubber, cork or
foam stoppers for the jars with small central holes in them
·
Thermometers that
read at least 20 to 40 degrees
celsius
·
Watch or stop
watch
·
Graduated
cylinder
·
Water
·
Clear sunny day
Procedure
1.
Fill each jar of
about half way with water, insert a thermometer and allow the water to reach
room temperature. Record this temperature on
2.
Outside, record
the temperature of the water again after about 20 minutes.
3.
View the jar from
the same angle that the Sun’s rays were approaching the jar and using a ruler
measure the height and width of the “target” presented by the water.
(approximate it as a rectangular area)
4.
Pour each jar of
water into a graduated cylinder to determine its volume. Record this in table 1
5.
Calculate the
energy gained by the Sun by each of the water samples, and the power delivered
by the Sun to each bottle.
6.
Calculate the
effective area (using the values obtained in step 4) of the water and determine
the power per unit area delivered by the sunlight. Compare this figure to the
standard average value of 1 kW/m2
Table 1
Bottle
Volume Mass
Start
Finish Change
Total Energy
Power
#
in liters (kg)
temp. temp.
temp.
time gained
(W)
Important formulas needed
1.
1 ml of water has a mass of 1 gram
2. The specific heat of water is 4180
joules/kg-celsius
3. Total energy gained in joules = mass (kg) of
water x specific heat x temperature change in C0
4. Power (W) = energy (J) / time (s)
Discussion Questions
1. How much energy did your samples of water
absorb from the sunlight?
2. What factors might have affected the amount
of energy the water absorbed from the Sun?
3. What results would you expect if you repeated
this experiment on Mercury or Mars (assuming that these planets had an
atmosphere similar to Earths)?
4. The Sun is a steady source of energy. What
might happen to Earth if the Sun was a variable star that changed its energy
output with time?
Standard A: Science as Inquiry
Standard B: Physical Science
Standard D: Earth and Space Science
Standard E: Science and Technology
Standard F: Science in Personal and Social
Perspectives
Standard G: History and Nature of Science
_________________________________________________________________
Standard
Activity to Address the
Standard
What the Activity Addresses
A
taking temp and dimensions
skills for scientific inquiry
B
observing the change in temp
transfer of energy
D
recording final data
earth in the solar system – sun in center
E
calculate energy and power gained by
bottle of water
abilities of technological design like solar panels
Standard 4
Key Idea 1: The Earth and
celestial phenomena can be described by principles of relative motion and
perspective
Performance Indicator 1.2
1.2b
Stars form from the gravitational collapse of interstellar gas clouds and
are powered by fusion energy