Problem Solutions with Force Diagrams
Many problems involving Newton's second law can be solved graphically, given a force diagram drawn to scale and a way of measuring the length and direction of the force arrows. For each problem of the following series, you are expected to draw a force diagram and use it to solve the problem graphically. To aid you in this, the magnitude and direction of the "active" force in the diagram (the brighter-colored one, most recently clicked on) are explicitly displayed. In addition, the magnitude and direction of the net force is also shown. Use the displayed values to find the information requested by the problem. The only numerical calculations you may need to perform are to divide the net force given in the diagram by mass to get acceleration, or to multiply acceleration by mass to get the net force that is needed in the diagram.
Use normal and frictional components (instead of a single contact force) where appropriate. The Red Dot is an indication of the sum of the forces (net force) that you have drawn at any given time. Briefly, from reading the problem you will need to determine whether the net force should be zero or not. Then change the direction and/or magnitude of one or more of the force vectors to put the dot at the center (for zero net force) or in the correct direction (for non-zero net force).