Newton's Second Law Model  

After students discover the cause of acceleration through hands-on labs, they are asked to develop a model with which they can reproduce the graphs they have seen during the lab activities.

Vensim Version STELLA Version Excel Version

[Diagram Level | Equations Level | Graphs ]

Distance(t) = Distance(t - dt) + (Rate_of_Change_of_Distance) * dt
INIT Distance = 0
Rate_of_Change_of_Distance = Velocity
Velocity(t) = Velocity(t - dt) + (Rate_of_Change_of_Velocity) * dt
INIT Velocity = 0
Rate_of_Change_of_Velocity = Acceleration
Acceleration = Net_Force/Mass
Mass = 5
Net_Force = 25
Time Specs Settings
Standard: Range 0-12; dt = 0.25; Integration Method = Euler's


In the first case, students are asked to keep the mass constant and vary the force. The first four graphs illustrate their findings. In the second case, the students are asked to keep the force constant and vary the mass. The next four graphs illustrate the results. The color coding is very important.

Force vs. Acceleration

Mass vs. Acceleration

Home | Contact | Site Map | Search