Game Development Reference
In-Depth Information
Figure 3-10.
The force diagram for the box on a ramp
Work
So far in this chapter, we have introduced the concept of a force and how a force is character-
ized by Newton's three laws of motion. In the remaining sections of this chapter, we will look
at some other fundamental physical concepts that are related to the concept of force. The first
topic we will introduce is that of
work
. In terms of physics, work is performed when a force,
F
,
is applied to an object over a distance,
d
.
W d
=
(3.14)
The physics definition of work may seem a bit strange because an object has to move for
work to be performed. If a person lifts a barbell over her head, she is performing work. If she
holds the barbell over her head without moving it, it may seem like work to her but in a physics
sense no work is performed. The amount of work performed is equal to the force component in
the direction that the object moves.
For an example of a work calculation, consider the situation shown in Figure 3-11 where
there is a box with a mass of 10
kg
sitting on the ground. The coefficient of friction between the
box and ground is equal to 0.5. There is also a cow and it is the cow's job to push the box hori-
zontally across the ground a distance,
d
= 2.0
m
.
Figure 3-11.
This is a mooving example.
