Some advice: The task in this exercise is to draw all force vectors in the individual free-body digrams for the three masses. To do this, select one of the 3 masses by clicking on the buttons "Show M1", "Show M2", or "Show M3", and then click on the forces that will appear on the lower left. Then you can draw a force vector by clicking somewhere on or near the mass and dragging the cursor. Concentrate on the direction of the force vectors only; the lengths of the vectors will be determined through calculations after the free-body diagrams are constructed. A vector is counted as correct, if its angle is within ±5° of the exact answer. If you click once on the "Check My Work" button, we display your total score; if you click again, you also see which vectors have the correct angles; if you click a third time, we show you the full answer. "Reset" will allow you to erase everything and start over.
© W. Bauer and G.D. Westfall, 2013