An air track is set up with a sonic ranger connected to a computer. The computer screen is projected for class visibility, and the computer will display any combination of position, speed and/or acceleration. The air track is inclined by placing one centimeter high blocks under the single-footed end of the track. The double-footed end is not lifted because the track is not stable on one foot. For angle determination, the air track feet are separated by exactly one meter.
Along with the usual downhill slide, it is also possible to push the glider uphill from the track bottom at a speed that does not get it all the way to the top. The comparison of speed and acceleration graphs will show that at the top of the travel the speed is zero and the acceleration is not.
NOTE: This demonstration can also be done with a fan cart on a dynamics track. The fan cart provides a visible force for students to see what accelerates the cart.
Click here for an instructional demonstration video using the fan cart.
