Method
Equipment
Set-Up
We set up our equipment by first placing a backdrop behind where we were going to take the pictures. We attached this backdrop to a table. In front of the backdrop, we placed a laser and photogate detector in line, so that when the laser's beam was broken, the flash would go off. The amount of delay between the triggering of the photogate and the flash was determined by a delay unit with a splitter. The two leads from the splitter went to flash units positioned symmetrically on either side of the stage, pointed towards the subject. The flash units were quenched by a paper clip short. The camera was positioned on a tripod in front of the stage, about 2 meters away, and about 50 cm above the ground. A cardboard tube was used to guide the falling objects to the impact site, and was held by a group member above the stage during experiments. The container of liquid nitrogen was placed on the table behind the stage, and the group member who's job it was to drop the objects stood on the table as well.
Set-Up Diagram
Procedure
Once our experiment was set up, we began taking photographs. To adjust the delay before the flashes, we found through trial and error the time it took for the falling objects to impact the ground, and then adjusted the delay unit accordingly. We used liquid nitrogen to freeze the food items. We then dropped these objects through a cardboard tube, past the photogate, and onto the target. When the objects impacted the ground, they usually broke into several pieces. The flash went off at around this time, and produced an exposure on the camera. We tried adjusting the delay to get different stages of the collision, and also experimented with changing the initial vertical velocity.
