In this study, a web site including instructional materials such as white sheet videos, simulations, and animations and problem solving materials such as true-false questions, fill-in-the-blanks, puzzles, open-ended and multiple-choice questions regarding such important physics units as "Force" and "Movement" was designed. The purpose was to investigate not only the effects of this web page on students' success in physics class but also the effects on their accomplishment levels of the objectives planned at the beginning of the class. An experimental design which included pre- and post-tests was used to measure the expected effects in this study. This study was conducted with 139 high school students (76 in the experimental group and 63 in the control group) in the academic year of 2008-2009. As a result of the analysis of the data collected, it was found out that there were statistically significant differences between both students' scores in the physics achievement test and their scores obtained from the check list of the students' gains in favour of experimental group (P less than 0.05). Analysis of the interviews held with 19 volunteering students demonstrated that although there were some technical problems experienced, the web site prepared helped the students learn the selected subjects. (Contains 7 tables and 4 figures.)