Analysis
1. Using the data graph of force/time from Part I, label the portion that corresponds to the block at rest, the time when the block just started to move, and the time when the block was moving at constant speed.
2. Still using the force/time data graph of Part I, compare the force necessary to keep the block sliding compared to the force necessary to start the slide.
3. The coefficient of friction is a constant that relates the normal force between two objects (blocks and table) and the force of friction. Based on your data graph from Part I, would you expect the coefficient of static friction to be greater than, less than, or the same as the coefficient of kinetic friction?
4. For Part II, calculate the normal force from the block with its added masses and enter it into the result tables.
Since the block is on a horizontal surface, the normal force will be equal in magnitude and opposite in direction to the weight of the block and any masses it carries. Careful with the units of force here as a Newton = Kg · m/s2
5. For Part II, calculate the average friction force over the three done for mass and enter it into the result tables.
6. Static Friction
Plot a result graph with the maximum static friction force along y-axis versus the normal force.
Since Fmaximum static = µsN the slope of this graph is the coefficient of static friction µs. Draw a single linear fit on your graph that best fits your data points. Find the numeric value of the slope, including any units. Should a line fitted to these data pass through the origin?
7. Kinetic Friction
Plot a result graph of the average kinetic friction force versus the normal force
Determine the coefficient of kinetic friction µk from the graph slope. Recall that Fkinetic = µkN . Consider if a line fitted to your data should pass through the origin.