Physics teachers recommend use of multiple representations while teaching students abstract physical contents based on perennial research. Diagrammatic representation and free body diagrams are very important to understand and for development of Newton’s mechanics. This study researches if students who draw free body diagrams are more successful than students who don’t while solving standard school exercises in Physics, as well as how the quality of their free body diagrams affects their success on problem solving. The study was carried out among first year high school students near Zagreb (N = 111), and the data was obtained from students’ results on solving six open ended tasks. There were two exam versions: version A explicitly required drawing of free body diagrams, version B didn’t. Results showed that, on average, respondents in group A got better results than those in the group B. When analyzing results by tasks it was observed that group A scored higher than group B in seven out of eight tasks. Likewise, students who drew quality free body diagrams, got more points in the test version A, while in version B a positive, but much weaker trend between quality of the diagram and successful solving, was also observed. The results of the research indicate the importance of multiple representations in Physics lessons and suggest Physics teachers to use them consistently and encourage construction of free body diagrams as a tool in application of Newtons’ laws.