Framed by a trebuchet, associate professor Kevin Kimball explains the process about to occur. Gallon jugs of water were catapulted onto the beach from the parking lot at Southern Maine Community College as graduates of Portland high schools participated in a summer prep course at SMCC, including a physics project involving the trebuchet.

With the catapult device called a trebuchet in the background, associate professor Kevin Kimball explains a physics exercise to the students in a summer prep course at SMCC for students who need remedial classes to prepare for college.

Associate professor Kevin Kimball tells a group about the physics exercise involving the trebuchet, right, as Portland high school graduates participate in a summer prep course at SMCC on Monday.

Zach Micheaud, left, a second-year computer science student at Southern Maine Community College, gets help from Jazmine Abasta from Deering High School to find the exact landing point of the water-filled jug that was hurled onto the beach by a trebuchet.