Game Development Reference

In-Depth Information

Figure 6-3. Target lower than launch point

Table 6-3
shows the formulas to use for this type of problem. Here again, almost all of

the formulas are the same as those shown in
Table 6-1
.

Table 6-3. Formulas—target lower than launch point

To calculate:

Use this formula:

x(t)

(v
o
cos φ) t

y(t)

(v
o
sin φ) t - (g t
2
) / 2

v
x
(t)

v
o
cos φ

v
y
(t)

v
o
sin φ - g t

v(t)

v
0
2

- 2
gtv
0
sin
φ
+
g
2
t
2

h

b + (v
o
2
sin
2
φ) / (2 g)

R

v
o
T cos φ

T

2
h

g

(v
o
sin φ) / g +

The only formulas that have changed are the formulas for
h
and
T
, which have been

revised to account for the difference in elevation between the target and the launch point

(except this time the target is lower than the launch point).

Finally, the fourth type of problem involves dropping the projectile from a moving

system, such as an airplane. In this case, the initial velocity of the projectile is horizontal

and equal to the speed of the vehicle dropping it.
Figure 6-4
illustrates this type of

problem.