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Physical Science 9
Unit 7: Physics is Moving
Activity #2: PHET, Moving Man
Learning Goals
Students will be able to accurately interpret and draw position, velocity and acceleration graphs for common situations
and explain their reasoning.
Preliminary Thinking with your Group
1. Accelerating objects are objects that are changing their velocity in any way. Brainstorm the three controls on an
automobile that cause it to accelerate.
2. An object is accelerating if it is moving _____. Circle all that apply.
a. with changing speed
b. extremely fast
c. with constant velocity
d. in a circle
e. downward
f. none of these
3. If an object is NOT accelerating, then one knows for sure that it is ______.
a. at rest
b. moving with a constant speed
d. maintaining a constant velocity
e. none of the choices
c. slowing down
Process and Procedures
Use Chrome. Google search “Moving Man phet”. Choose Download now. In Moving Man you will work with a
PHET simulation to simulate different motions and analyze the graphs associated with those motions.
1. Select the Intro tab. Investigate Moving Man by using the sliders to move the man. The pause and play buttons
will be used frequently. Try the playback features and the vector features.
2. After you have explored for a while, switch to the Chart tab. Add values to the boxes on the right to make your
man move in different ways. Use the playback features to carefully examine the graphs and determine what
motion corresponds to particular features of the graph. While you make observations talk with your partner about
the reasons the graphs look the way they do.
3. Predictions. Examine the coordinate graphs below and consider the scenario. Without using Moving Man, sketch
what you think the graphs would look like for the following scenario and explain your reasoning with your partner.
Scenario A: The man starts at the tree and moves toward the
house with constant velocity
Position - time graph
Velocity - time graph
Acceleration - time graph
Corrections to your
predicitons
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4. Complete the charts for each of the following scenarios. Predict what you think the graphs will look like, and then
use Moving Man to verify or correct your predicted graphs and reasoning with a different color pen.
Scenario B: The man starts three meters from the house and accelerates towards the tree.
Position - time graph
Explain your reasoning for your prediction
Velocity - time graph
Explain your reasoning for your prediction
Acceleration - time graph
Explain your reasoning for your prediction
Scenario C: The man stands still while he talks on his cell phone at the middle of the sidewalk, then
walks toward the house at a constant rate trying to get better cell reception. He comes to a sudden stop
when the coverage is good (about a meter before the house) and stands still to finish his conversation.
Position - time graph
Explain your reasoning for your prediction
Velocity - time graph
Explain your reasoning for your prediction
Acceleration - time graph
Explain your reasoning for your prediction
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Scenario D: The man starts close to the house, stands still for a little while, then walks toward the tree
at a constant rate for a while, then the slows to a stop.
Position - time graph
Explain your reasoning for your prediction
Velocity - time graph
Explain your reasoning for your prediction
Acceleration - time graph
Explain your reasoning for your prediction
Scenario E: A man wakes up from his nap under the tree and speeds up toward the house. He stops because
he is worried that he dropped his keys. He stands still as he searches his pockets for his keys. Once he finds
them, he continues calmly to walk toward the house and then slows to a stop as he nears the door.
Position - time graph
Explain your reasoning for your prediction
Velocity - time graph
Explain your reasoning for your prediction
Acceleration - time graph
Explain your reasoning for your prediction
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5. Answer the following questions in your own words while thinking about the activity you just completed. (You may
draw a picture to help explain your answers.)
a. Describe/define position.
b. Describe/define velocity.
c. What is a vector?
d. Describe/define acceleration.
e. Describe/sketch how the man could have positive position while having a negative velocity.
f.
Describe/sketch how the man could have negative position while having a positive velocity.
g. Describe/sketch how the man could have positive position while having a positive velocity.
h. Describe/sketch how the man could have negative position while having a negative velocity.
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(-)
(-)
(-)
(0) (+)
(0) (+)
(0) (+)
0
0
0
Velocity
a. position:
velocity:
acceleration:
Position
Stop-n-Think
1. For each set of graphs, both the position vs time and velocity vs time graphs represent the same motion. Decide
what the initial values are for position and velocity. For acceleration decide the general value for the motion
shown. Choices are either negative, zero or positive.
0
(-)
(-)
(-)
(0) (+)
(0) (+)
(0) (+)
0
0
0
0
0
0
(0) (+)
(0) (+)
(0) (+)
0
0
0
0
0
0
Velocity
(-)
(-)
(-)
Position
Time
c. position:
velocity:
acceleration:
0
0
0
Time
(0) (+)
(0) (+)
(0) (+)
0
0
Time
0
0
Time
0
0
0
0
0
Time
0
0
0
0
0
0
0
0
0
Velocity
(-)
(-)
(-)
Position
d. position:
velocity:
acceleration:
0
Time
Velocity
b. position:
velocity:
acceleration:
Position
Time
Time
2. Describe the motion when velocity and acceleration have the same sign. Does it matter if both are positive
or both are negative?
3. Describe the motion when velocity and acceleration have opposite signs. Does it matter which is positive
and which is negative?
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Physical Science 9
Activity #2: PHET, Moving Man
Reflect and Connect