71
4-4 PROJ ECTI LE M OTION
A
x
y
O
0
θ
v 0
v 0y
v 0x
y
O
x
O
v x
v y v
x
y
y
O
v y = 0
v
x
y
O
v x
v y
v
x
y
O
v x
x
O v 0x
x
O
v x
x
O
v x
x
O
v x
x
O
v x
y
O
v 0y
O
v y
y
y
O
v y = 0
y
O
v y
y
v x
v y
θ
v
v x
v y
Vertical motion
Vertical velocity
Launch
Launch
Speed decreasing
Constant velocity
Speed increasing
Constant velocity
Constant velocity
Stopped at
maximum
height
Constant velocity
+
➡
Horizontal motion
Projectile motion
Launch velocity
Launch angle
This vertical motion plus
this horizontal motion
produces this projectile motion.
Figure 4-9 The projectile motion of an object launched into the air at the origin of a coordinate system and with launch
velocity at angle u 0 . The motion is a combination of vertical motion (constant acceleration) and horizontal motion
(constant velocity), as shown by the velocity components.
v
:
0