BANG! BANG! Pine Tree physics class targets bullet's velocity
By Robyn Claridy firstname.lastname@example.org
Feb. 15, 2011 at 6 p.m.
"Fingers in ears!" Range Master Danny Butler yelled before firing rounds into a make-shift ballistic pendulum built by 10 Pine Tree senior advanced placement physics students Tuesday afternoon.
The experiment, which physics teacher Joe Kirchhoff called a "poor man's radar gun," was performed to test the velocity of the bullet as it passed through the target at the Longview Police Department's firing range.
For about a week the students collaborated in different groups within the classroom to design their ideal model for the experiment, Kirchhoff said.
"One group was in charge of designing the target and another was in charge of building the wooden structure which held the target. There was also a group in charge of the experiment's calculations," senior Jared Smart said.
The target was designed out of a plastic foam cooler with pieces of carpet fitted vertically along with a bullet proof vest to help slow the bullet as it passed through the target.
Students described the experiment as a real world application of physics.
"It was fun and neat to see how physics works in real life," senior Josh Schulik said.
"Any experiment with bullets is cool," senior Chris Green said.
After the swing was assembled, students stayed behind the firing line with their fingers pressed in their ears while Butler fired rounds into the target with different guns including a few rifles and a handgun.
All hands remained on deck through out the entire experiment, each time a round was fired the students hustled to the target, after the zone was clear to see where the bullet was halted in the target.
Longview Police Officer Chris Bethard, who also serves as the Pine Tree school resources officer, said the police department was always willing to help schools when it offered real world application.
Kirchhoff said technology has made the ballistic pendulum an obsolete experiment, but showed how accurate physics was.
"It's a textbook problem, but I wanted the students to see it in reality," he said.
Now that the experiment is over, the class will review the video of the experiment in slow motion to see how high the plastic foam pendulum reached with the different bullets.
Longview police range officers were on site to ensure the experiment was conducted in a safe manner, police officials said.