ASTRONOMY
10 THIRD
HOUR SESSION “A” 
NAME 
KEYA 






ACTIVITY: Cosmic Scales 
DATE 

ID# 

Answer
the following questions about scales (the objects in the blanks will be given
in class):
1. If one edge of cube A is __5__ times
longer than one edge of cube B, and one edge of cube B is ___7__ times
longer than cube C (exhibited on front desk),
then how long is one edge of cube A?
Would it fit in the classroom?
3500 mm (320 cm) i.e. factor 1 x factor 2 x cube C length 
no 
2.
What is the volume of cube A?
(factor 1 x factor 2)^{3}x(100 mm)^{3}=4.2875x10^{10} mm^{3} 
3. What is the diameter of the marble? What is
its radius?
What is its volume?
16 mm 
8 mm 
(4/3)p x (8 mm)^{3 }~ 2145 mm^{3} 
4. About how many marbles would fit in cube A? (Disregard the effects of air gaps between
marbles.) Considering the accuracy of your
ability to measure the size of your marble, what might be a more realistic
guess for how many marbles could fit in cube A?
1.9988x10^{7} 
2.0x10^{7} = 20,000,000 
5. What
is the ratio of diameters between the planets ____Venus_____
and ____Mars_____? Suppose
the marble you were given in class represented the size of the planet __Venus___. What
diameter (mm) marble would be required to represent the size of the planet___Mars__?
1.78 
marble diameter (mm)/1.78 = 8.98 mm~9.0
mm 
6. Estimate how many people set endtoend
would reach from the Earth to _____ the Moon____
? Do we have enough people in __the U.S__ to do this?
200 to 250 million 
yes 
7. Rewrite your first answer from question #6
in scientific (exponential) notation.
2.0 x
10^{8} to 2.5 x 10^{8} 
8. The distance from the Earth to the Sun is 1
Astronomical Unit (AU). What is the
distance from the Sun to ___(current position of)
Voyager 1__ in AU's? Give Voyager 1 distance to students= 20,570,000,000
km . 1 AU = Find in Appendix A
137.5 AU 
Open
the web site http://htwins.net/scale2/scale2.swf?bordercolor=white
and click “START.” Notice the grey ring that is 1 meter in diameter.
9. Slowly drag the slider near the bottom of
the screen to the left until you see another circle appear. What size does this
circle represent?
10^{3} m = 0.001 m = 1 mm 
10. Drag the slider to the left, until another ___ _5______
grey rings appear; the number in the lowerright part of the screen should be
___ 10^{15}______.
What objects are approximately this size?
Proton or neutron 
11. Drag the slider to the right, until the number
in the lowerright part of the screen reads ____10^{6}______.
What is the smallest astronomical body just outside the grey ring?
Ceres 
12. Drag the slider until the number in the
lowerright part of the screen reads 10^{19.4}; you will start to see
the smallest galaxies. Continue moving the slider to the right until you see __ The Milky Way _____. How large is it in meters?
10^{21} meters (Zettameter)
or 1.2
x 10^{21} meters (if clicked on) 