4-4 PROJECTILE MOTION 71
A
x
y
O
θ 0
v 0
v 0 y
v 0 x
y
O
x
O
vx
vy v
x
y
y
O
vy= 0
v
x
y
O
vx
vy v
x
y
O
vx
x
O v 0 x
x
O vx
x
O
vx
x
O
vx
x
O
vx
y
O
v 0 y
O
vy
y
y
O
vy= 0
y
O
vy
y
vx
vy θ
v
vx
vy
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 4-9The projectile motionof 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