PHY 101 Gizmo-Based Student Exploration (Grade A)

Summary:

The text describes a student exploration activity using the Free-Fall Laboratory Gizmo. The Gizmo allows students to measure the motion of objects in free fall and explore concepts such as acceleration, air resistance, velocity, and terminal velocity. The activity involves conducting experiments, making observations, forming hypotheses, and analyzing data to understand the factors that affect how quickly objects fall. It also explores the relationship between acceleration, distance, and time in free-falling objects. The activity concludes with applying the learned rules to solve problems related to falling objects.

Excerpt:

PHY 101 Gizmo-Based Student Exploration

Student Exploration: Free-Fall Laboratory
Vocabulary: acceleration, air resistance, free fall, instantaneous velocity, terminal velocity, velocity, vacuum

Prior Knowledge Questions (Do these BEFORE using the Gizmo)
1. Suppose you dropped a feather and a hammer simultaneously. Which object would hit the ground first? A hammer, because the feather would be affected by air resistance.
2. Imagine repeating the experiment in an airless tube, or vacuum. Would this change the result? If so, how? They’d hit the ground simultaneously because no air equals no air resistance.

Gizmo Warm-up
The Free-Fall Laboratory Gizmo™ allows you to measure the motion of an object in free fall. On the CONTROLS pane, check that the Shuttlecock is selected, the Initial height is 3 meters, and the Atmosphere is Air.

1. Click Play ( ) to release the shuttlecock. How long does it take to fall to the bottom? 0.90 seconds

2. Select the GRAPH tab. The box labelled h (m) should be checked, displaying a graph of height vs. time. What does this graph show? It starts at 3 and curves down to 0 around 0.75.

3. Turn on the v (m/s) box to see a velocity vs. time graph. Velocity is the speed and direction of the object. Velocity is also referred to as instantaneous velocity. Because the shuttlecock is falling downward, its velocity is negative.

Does the velocity stay constant as the object drops? No.

4. Turn on the a (m/s/s) box to see an acceleration vs. time graph. Acceleration is the rate at which the velocity changes over time. What does this graph show? The acceleration curves up from just above -10.