HP 15c Collector's Edition

40 Section 3: The Memory Stack, LAST X, and Data Storage
Example: Two close stellar neighbors of
Earth are Rigel Centaurus (4.3 light-
years away) and Sirius (8.7 light-years
away). Use the speed of light, c (3.0 × 10
8
meters/second, or 9.5 × 10
15
meters/year), to figure the distances to
these stars in meters. (The stack
diagrams show only one decimal place.)
T
t z y y
Z
z y x x
Y
y x
4.3 4.3
X
x
4.3 4.3 9.5 15
Keys:
4.3
v
9.5 “ 15
LAST X:
/
/ / /
T
y y y x
Z
x y x
4.1 16
Y 4.3
x
4.1 16 8.7
X 9.5 15 4.1 16 8.7 9.5 15
Keys:
*
8.7
| K
LAST X:
/
9.5 15 9.5 15 9.5 15
T
x x
Z 4.1 16
x
Y 8.7 4.1 16
(Rigel Centaurus is
4.1 × 10
16
meters away.)
(Sirius is 8.3 × 10
16
meters away.)
X 9.5 15 8.3 16
Keys:
*
LAST X: 9.5 15 9.5 15