The museum added a hands-on Time Of Flight exhibit demonstrating how an oscilloscope can be used to measure the velocity of a marble.  The exhibit consists of a ramp that can be set at three different heights to roll a marble down.

The ramp has a pair of optical sensors 1/2 meter apart.  A 7623A storage oscilloscope displays the pulses generated by the two sensors. You then measure the time between the two pulses and multiply by two to obtain the velocity in meters/second.

 

We have exhibited this time of flight demonstration at the Beaverton Library Science Geek Out Fest and also at MESA. The kids enjoy experimenting and understanding how the exhibit works.