Texas Instruments TI-89 - Preview of Constants and Measurement Units

82 Chapter 4: Constants and Measurement Units
04UNITS DOC TI
-
89/92Plus: Constants and Measurement Units (English) Susan Gullord Revised: 02/23/01 10:54 AM Printed: 02/23/01 2:12 PM Page 82 of 12
Steps
³
TI
-
89
Keystrokes
›
TI
-
92 Plus
Keystrokes Display
1. Display the
MODE
dialog box,
Page 3
. For
Unit System
mode,
select
SI
for the metric system of
measurements.
Results are displayed according to
these default units.
3…B
1
¸
3…
B
1
¸
2.
Create
an acceleration unit for
meters/second
2
named _ms2.
The UNITS dialog box lets you select
units from an alphabetical list of
categories. You can use
2D
and
2C
to scroll one page at a time
through the categories.
Now, instead of re-entering
_m/_s
ñ
each time you need it, you can use
_ms2 .
Also, you can now use the UNITS
dialog box to select
_ms2 from the
Acceleration category.
29DB
M
¸
e29
DDDB
S
¸
Z
2
§
¥
2™
MS
j
2
¸
¥
9
DB
M
¸
e
¥
9
DDDB
S
¸
Z
2
§
2

MS
2
¸
3. Calculate the force when
m = 5 kilograms (_kg) and
a = 20 meters/second
2
(_ms2).
If you know the abbreviation for a
unit, you can type it from the
keyboard.
5
¥
2™
KG
jp
20
¥2™
MS
j
2
¸
5
2

KG
p
20
2

MS2
¸
4. Using the same m, calculate the
force for an acceleration due to
gravity (the constant _g).
For _g , you can use the pre-defined
constant available from the UNITS
dialog box or you can type
_g .
5
¥
2™
KG
jp
29B
j
G
¸¸
5
2
KG
p
¥
9
B
G
¸¸
5. Convert to kilograms of force
(_kgf).
2
displays the
4
conversion
operator.
B2¥
2™
KGF
j¸
B
22
KGF
¸
Preview of Constants and Measurement Units
Using the equation f = m
ù
a, calculate the force when m = 5 kilograms and a = 20
meters/second
ñ
. What is the force when a = 9.8 meters/second
ñ
. (This is the
acceleration due to gravity, which is a constant named _g). Convert the result from
newtons to kilograms of force.
If you use the UNITS
dialog box to select a
unit, the _ is entered
automatically.