Datasheet

Page 24· Applied Robotics with the SumoBot
Since weight is a force, and gravity is a form of acceleration, an equation you will find
useful in your calculations is:
gmW ×=
The acceleration due to gravity is 9.8 m/s
2
in the SI system and 32 ft/s
2
in the British
Engineering system.
Problem: An object has a mass of 0.75 kg, what's its weight in newtons?
Solution: Start with the equation w = mg, and figure out which system to use and which
pieces of information you already know. Also, look at Table 1-1 again. The units of your
result should be in kg×m/s
2
. Since the mass is in kg units, we can start with the SI
system. The acceleration due to gravity in the SI system is 9.8 m/s
2
. Now that we know
two pieces of the puzzle, we can calculate the third.
N35.7
s/mkg35.7
s/m8.9kg75.0
mgw
2
2
=
=
×=
=
A newton is in fact a kg m/s
2
. Likewise, a pound is a slug ft/s
2
.
Unit Conversions
There are 1000 grams in 1 kilogram. That's:
kg1g1000 =
If you divide both sides of the equal sign by one of these values, you will have 1 =
conversion factor. For example:
1
kg1
g1000
and
g1000
kg1
1 ==