Title: Net Force Purpose: To practice determining the net force acting on objects. To practice calculating velocity and acceleration. To practice constructing position vs time and velocity vs time graphs. Website: http://www.physicsclassroom.com/Class/newtlaws/U2L2d.html Materials: centimeter ruler calculator (Scientific Calculator Online) Procedure: Identify whether or not there is a net force on cars 1, 2, and 3. Use the centimeter ruler to determine if velocity is constant. consider that the intervals between dots is 1 second. measure the distance between dots. measure to 2 decimal places! Calculate velocity and acceleration for each car! Construct a position vs time graph for each car. Construct a velocity vs time graph for each car. Go to http://www.physicsclassroom.com/Class/newtlaws/U2L2d.html to check your answers about net force! (you need to scroll to the bottom of the page...but you can read the information about forces as well!)
car 1

car 2

car 3

Results: These will be your data charts and graphs. (you may construct your graph by hand or use Excel)

Construct a data chart similar to the one below for each car!

 Car #___________ Time (s) Distance (cm) Velocity (cm/s) Acceleration (v/s) 1 . . 2 . . 3 . . 4 . . 5 . . 6 . . 7 . . 8 . . 9 . . 10 . . 11 . . 12 13 14 15 * remember units

Discussion:

• Summarize what you did.
• Comment on the difficulties of measuring distance.
• Indicate which cars showed constant velocity and which showed acceleration.
• Indicate which cars showed a net force.
• Indicate whether or not you correctly identified the cars which were acted upon by a net force.
• Comment on sources of error.
• Suggest improvements.

Conclusion: (not required)

Reflection: (personal commentary on what you learned from the activity and/or its application to real life)

Animated Graphics Courtesy of
Jo's World