Teaches physics concepts of force, speed, and mass. For Ages 8-12.
Duration: 1 hour
Elementary (ages 8-10)
Middle School (ages 11-13)
MODULES & ACCESSORIES USED (6)
dc motor (2)
battery + cable (1)
OTHER MATERIALS USED (4)
Balsa wood (we used 3/16″ thick) 1
Balsa wood stick for rear shaft (we used 1/8″ thick) 1
LEGO wheels 1
Sugru (silicone modeling clay) 1
STEP 1 : Weigh in
Take your littleBits car and weigh it on the scale. Note the weight in kilo-grams.
STEP 2 : Length
Note the length of the ramp in meters
STEP 3 : Roll it!
Place the ramp flat on the floor. Time how long it takes the car to go across the ramp.
STEP 4 : Create an incline
Position the ramp so that it is at an incline of approximately 5° (you can either have someone in your group hold it there, or you can prop the ramp up somehow). Run the car across the ramp again, timing how long it takes. Do you notice any difference?
STEP 5 : Increase the incline
Increase the incline of the ramp by another 5° and run the car up the ramp, again noting time and any difference you experience
STEP 6 : Continue climbing…
Continue this process until the car is no longer able to move up the ramp, or the ramp is at such a steep incline that the car does not stay on the ramp without falling backwards off the ramp
STEP 7 : Stalled?
At what angle was the car no longer able to move up the ramp?
STEP 8 : Let’s analyze
Using the data you’ve collected and all your physics knowledge to date, is there any way to calculate the force or power of the motors on the car? If so, try to give an estimate of what you believe the force to be. If there is no way to calculate the force/power of the motors, then explain what information you would need that you don’t have in order to come up with the answer.
STEP 9 : Use littleBits
Since the amount of electricity that powers the motors is con-trolled by the amount of light a sensor in the middle of the car receives, is there a way you could use the littleBits starter kit to make your car move slowly, medium quick, or as fast as it can? (Consider how an LED and a potentiometer near the light sensor in your car might act as a controller.)
STEP 10 : Repeat the experiment
If you can get a speed controller working with the littleBits star ter kit, then weigh your car again (including the controller) and run the experiment again
STEP 11 : Reflect
Throughout this experiment, did everything happen the way you expected it to? If so, lucky you! If not, what factors do you think contributed to the discrepancies in your outcomes? Physics often relates to ideal situations and perfect scenarios – what about this experiment would account for derivations from your anticipated outcome?