Science Starter!
There is an interesting monkey at the zoo. The zookeeper feeds the monkey by shooting
bananas from a banana cannon to the monkey in the tree. This particular monkey has a habit of
dropping from the tree the moment that the banana leaves the muzzle of the cannon. If the
monkey lets go of the tree the moment that the banana is fired, will it catch the banana?
Describe what you believe will happen and why.
Two Dimensional Motion
KEY IDEA: Horizontal motion and Vertical motion are INDEPENDENT of each other.
“Cliff” problems:Vertical Motion: ay = - 9.8 m/s2 (Free – Fall)
Horizontal Motion: ax = 0 m/s2
Kinematics Equations
Horizontal Vertical
Vertical Horizontal
Time ay (m/s2) vy (m/s) y (m) ax (m/s2) vx (m/s) x (m)
0 s - 9.8 0 78.4 0 20 0
1 s - 9.8 - 9.8 73.5 0 20 20
2 s - 9.8 - 19.6 58.8 0 20 40
3 s - 9.8 - 29.4 34.3 0 20 60
4 s - 9.8 - 39.2 0 0 20 80
0 0.5 1 1.5 2 2.5 3 3.5 4 4.50
5
10
15
20
25
Time (s)
Hor
izon
tal V
eloc
ity
(m/s
)
0 0.5 1 1.5 2 2.5 3 3.5 4 4.50
10
20
30
40
50
60
70
80
90
Time (s)
Hor
izon
tal P
ositi
on (m
)
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
-45
-40
-35
-30
-25
-20
-15
-10
-5
0
Time (s)
Verti
cal V
eloc
ity
(m/s
)
0 0.5 1 1.5 2 2.5 3 3.5 4 4.50
10
20
30
40
50
60
70
80
90
Time (s)
Verti
cal P
ositi
on (m
)
Representing Quantities
Vectors:Remember: Any quantity with magnitude and direction (Displacement, Velocity, Acceleration)Represented by an ARROW, that is proportional in size and direction.
V = 5 m/s EastV = 2 m/s North
Actual Velocity
At t = 2s:
Vx = + 20 m/sVy = - 19.6 m/s
Resultant Vectors
Pythagorean Theorem:= +
Vx
Vy V
Problem Solving
1. Draw a picture and include labels!2. List variables in “x” and “y” directions
SEPERATELY!