Part V  Ball Tossed into the Air

Part V  Ball Tossed into the Air

1. Place the motion detector on the floor pointing toward the ceiling, as shown in Figure 3. Place a protective wire basket over the motion detector.

Figure 3   

0. Sketch your predictions for the position vs. time and velocity vs. time graphs of a ball thrown straight up into the air. Will the acceleration be constant? Will it change direction? Will there be a point where the acceleration is zero?

1. Hold the rubber ball with your hands on either side, about 0.5 m above the motion detector.

2. Click or tap Collect to start data collection, then gently toss the ball straight up over the motion detector. Move your hands quickly out of the way so that the motion detector tracks the ball rather than your hand. Catch the ball just before it reaches the wire basket.

3. If you do not see a smooth graph, the ball was most likely not in the beam of the motion detector. Make adjustments and repeat Steps 3–4 until you get a smooth graph.

4. Proceed to the Analysis questions for Part V.

Analysis

Part V  Ball Tossed into the Air

1. Export, print, or sketch the portions of the position and velocity graphs that represent the time the ball was in the air. Compare these to your predicted graphs and comment on any differences.

2. Was the acceleration constant or changing? How can you tell?

3. Identify three positions of the ball: when it was on the way up, at the top, and on the way down. For each section, apply a linear curve fit to determine the slope (acceleration). To apply a linear curve fit, select a region of data, click or tap Graph Tools, . Choose Linear, and click or tap Apply. Do this for each of the three positions. What did you discover?

4. Was there any point in the motion where the velocity was zero? Explain.

5. Was there any point in the motion where the acceleration was zero? Explain.