Name
Period
Date
One-Dimensional Projectile Motion Activity
•
•
•
•
Open the Data Studio File 1D Projectile Motion.
Remember, the motion detector thinks of itself as 0 position, it is set to read down
as the negative direction and up as the positive direction and there is a 15 cm
“dead zone” below the motion detector.
You only have 2.0 s to complete a trial.
You may need to do several trials until you get one that is clear. The ball must
stay directly under the motion detector. Practice before you use the computer!
1. Speeding up while free-falling
a. Observe the motion of the ball starting from rest and falling without using the motion detector.
b. Predict the graphs describing
the motion as the ball falls.
+
0
t
0
+
t
velocity
velocity
+
0
+
+
-
t
acceleration
-
acceleration
-
0
d. Draw a motion map including
position dots, velocity
arrows and acceleration
arrows for the falling ball.

y
position
t
position
+
0
c. Record the graphs as
displayed by the motion
detector as the ball falls.
0
t
t
-
e. Do a linear fit on the portion of the velocity vs. time graph when the ball is falling and record the
acceleration of the falling ball with units.
Acceleration =
f. Write a sentence that describes the meaning of the acceleration.
1D Projectile Motion Activity
page 2
2. Up and Down below the motion detector
a. Drop the ball and let it bounce at least once. The entire motion must be directly under the motion
detector. The motion of the ball after it bounces off of the floor can be analyzed as the ball moving
up and then down below the motion detector.
b. Predict the graphs describing
c. Record the graphs as displayed d. Draw a motion map including
the motion of the ball after it
by the motion detector after
position dots, velocity arrows
bounces off of the floor. The
the ball bounces off of the
and acceleration arrows after
dotted line represents the
floor. The dotted line
the ball bounces off of the
time the ball reaches its
represents the time the ball
floor.
highest point.
reaches its highest point.
+
0
t
t

y
position
position
+
0
0
+
t
velocity
velocity
+
0
+
+
0
t
acceleration
-
acceleration
-
0
t
t
e. Do a linear fit on the portion of the velocity vs. time graph when the ball is rising and then falling and
record the acceleration of the ball with units.
Acceleration =
1D Projectile Motion Activity
page 3
1. Circle the correct sign and then determine whether the ball is speeding up, slowing
down or changing directions during each part of its motion.
On the way up
At the top
On the way
down
Velocity
+
-
0
+
-
0
+
-
0
Acceleration
+
-
0
+
-
0
+
-
0
Speeding up, slowing down or
changing directions?
2. Draw and label a force diagram for the ball for each part of its motion. Neglect air
resistance.
On the way up
At the top
3. Consider experiment #2.
a. Is the acceleration of the ball the
same on the way up, at the top and
on the way down?
On the way down
b. Justify your answer.
4. Consider the highest point of the ball’s motion.
a. What is the velocity of
b. Is it accelerating?
the ball?
How do you know?
c. What is the ball doing?
5. If this experiment was supposed to model true projectile motion, why wasn’t the
magnitude of the ball’s acceleration exactly 9.8 m 2 ?
s