On March 31, 2001, at 0946 hours Pacific standard time, a Cessna 170B, N4315B, sustained substantial damage when it nosed over during landing roll at Lincoln Airport, Lincoln, California. Visual meteorological conditions prevailed and no flight plan had been filed for the instructional flight, which originated from Lincoln Airport approximately 0815. The flight was operated under the provisions of 14 CFR Part 91 by a certified flight instructor who, along with his dual student, was not injured. The flight instructor stated that he was sitting in the left seat and the dual student was sitting in the right seat. The accident occurred on a stop-and-go which was being performed by the dual student. The approach and touchdown were normal. After touchdown, the flight instructor verified that the throttle was at idle and that the yoke was fully aft. The dual student gradually braked. As the airplane slowed, the tail suddenly began to rise and the propeller struck the ground and the airplane nosed over.