Java Reference
In-Depth Information
CHALLENGE 3.1
Complete the class diagram in Figure 3.2 to show the design of a
ShellAsRocket
class that lets a
Shell
object participate in a simulation as a
RocketSim
object.
Figure 3.2. You can adapt a shell's methods to meet the needs of a rocket
simulation.
Units of Measure
The classes and interfaces in the
com.oozinoz.units
package help developers at
Oozinoz to prevent unit conversion errors. Rather than using
double
to represent
everything from inches of length to pounds of force, the Oozinoz developers have
created a sophisticated object model for measurements.
A
measure
is a combination of a magnitude and a dimension. A
dimension
is an
aggregation of a measure's length, mass, and time exponents. For example, a
volume, such as one ft
3
, is three dimensional in length. An acceleration of 9.8
meters/second
2
has a length dimension of 1 and a time dimension of -2. The
units
package models commonly used dimensions, as Figure 3.3 shows. Note that the
subclasses of
Measure
are dimensions, such as
Length
and
Force
, not units,
such as inches and pounds.
