1. Rubber Band Powered Dragster
Shaw STEM Lab 2017

2. K’Nex Basic
If you’ve never used K’Nex before, read over these instructions to help you get started!

3. *Check Out

7. Research: Part 1
Attach ONE rubber band to the rear axle of your racer and turn the axle two full rotations.
Place your racer on the floor and measure the distance and time that the vehicle travels. Repeat for a total of three times. Calculate the speed of your dragster.
Compile your information into a table.
Test #
Distance
Time
Speed 1. 2. 3.

8. Research: Part 2
Attach BOTH rubber bands to the rear axle of your racer and turn the axle two full rotations.
Place your racer on the floor and measure the distance and time that the vehicle travels. Repeat for a total of three times. Calculate the speed of your dragster.
Compile your information into a table.
Test #
Distance
Time
Speed 1. 2. 3.

9. Newton’s Second Law of Motion
Newton’s Second Law of Motion is the Law of Force, Mass and Acceleration. From this we get the equation F=ma.
Force is measured in Newton’s, mass is measured in kilograms and acceleration is measured in meters per second2.
Let’s apply Newton’s Second Law to our dragster!

10. Newton’s Second Law of Motion
Before we can calculate Newton’s Second Law, we need to understand Velocity.
Velocity is like speed, but it is in a specific direction. Examples: North, Southwest, etc.
For example, if we wanted to calculate the Velocity of a car traveling east meters in 1.22 seconds it would look like this:
3.48 meters / 1.22 seconds = 2.85 meters per second east
Note that we include which direction our car was moving in our units!
Velocity = Distance
(In a specific direction)
Time

11. Newton’s Second Law of Motion
Next, let’s investigate Acceleration. The formula is below.
Given that the car is not moving at the start line, the Initial Velocity is zero (0).
Acceleration = Velocity Final (m/s) – Velocity Initial (m/s)
Time

12. Research: Part 3
Find the mass of your dragster and enter it into a data table.
Be sure to convert from grams to kilograms!
See Example Data Table on next slide.
Wind the rubber band the specified number of rotations.
Record the distance and time your dragster traveled.
Calculate the velocity and acceleration for each trial.

13. Research: Part 3 Vehicle Mass: __________ g Vehicle Mass: __________kg
# of Rotations
Distance (m)
Time (seconds)
Velocity (m/sec)
Acceleration (m/s2) 1 2 3 4 5