6.1 Notes Days 1 – 2: Projectile Motion
Q: What is a projectile?
Q: What is a trajectory?
Q: What is a vector component?
Q: How do you solve for the magnitude of a vector component given the initial
value and ?
Q: When is the velocity for a projectile in flight minimized? Maximized?
When is it zero?
Q: What single variable allows you to equate motion in the x – direction
(horizontal) with motion in the y – direction (vertical)? Why?
Q: What is true of the magnitudes of the horizontal and vertical components
of velocity for a projectile? Why?
Whenever you do a projectile motion problem, you should always draw and
label a picture of the initial set – up, and the supposed trajectory. You should
also decide on the type of launch. There is morr than one way to launch a
projectile. No matter what the launch type, you may find the chart below
particularly helpful!! Use it in combination with the basic kinematics
equations and you’re all set!
Basically, we consider the following two scenarios:
1. Horizontal Launch
2. Angular Launch
Horizontal Launch
Ex 1) A cannonball launcher is placed on top of a 125 m high cliff. The
launcher then fires a ball horizontally at a rate of 96.7 m/s. How long is it in
the air? How far does it move in the horizontal direction?
X
v.I
Y
0 m/s
constant
horizontal
v.f
a
d
t
0 m/s2
-9.81m/s2
constant
Angular Launch
Q: What are the only differences with respect to the motion?
A: v0 must be resolved into vi.x and vi,y
You may still use the table!
Ex 1, p 151
A ball is launched at 4.5 m/s at 660 above the horizontal. What is the
maximum height reached by the ball? How long is it in the air? What is it’s
horizontal range?
Ex 2) Consider that same ball being launched from the top of a 125 m cliff,
and being allowed to reach the ground below. How long is it in the air? What
is it’s horizontal range?