Gizmos Student Exploration: Ripple Tank ALL ANSWERS 100% CORRECT FALL-2021 GUARANTEED GRADE A+

Directions: Follow the instructions to go through the simulation. Respond to the questions and prompts in the orange boxes. Vocabulary: constructive interference, crest, destructive interference, diffraction, Huygens’ Principle, interference, law of superposition, node, refraction, trough, wave, wavelength Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. The image below shows small ripples, or waves, moving through water in a pond. Highlight the description below that you think describes the motion of a wave most accurately. A. Each wave consists of a set of water molecules moving outward from the center. B. When a wave passes, water molecules move up and down before returning to near their original position. 2. Waves have crests (high points) and troughs (low points). The wavelength of a wave is the distance between adjacent crests (or troughs). Label the crests, the trough, and the wavelength on the image at left. Gizmo Warm-up A ripple tank, such as the one shown in the Ripple Tank Gizmo, is a shallow pan of water with a vibrating motor that produces waves. The tank is lit from above so that the wave crests and troughs are visible. Ripple tanks are particularly useful because many properties of water waves are shared by other kinds of waves that are harder to see. Check that Open tank is selected and the Wavelength is 4.0 cm. Click Play ( ) and observe. Click Pause ( ) when the first wave reaches the right edge of the tank. 1. The light regions represent troughs while the dark areas represent crests. 2. Click Reset ( ). Set the Wavelength to 16.0 cm, and click Play. Click Pause when the waves reach the edge. How did increasing the wavelength affect the shape and speed of the waves? Activity A: Wave motion Get the Gizmo ready: ● Select Barrier with 3-cm gap from the Scenario menu. Question: What causes wave motion? 1. Predict: In this activity, you will test two hypotheses for wave motion. Circle the hypothesis you think is closest to the truth. Hypothesis 1: Waves are sets of particles moving together due to their forward momentum. Hypothesis 2: Waves occur when particles transmit energy to other particles in all directions but don’t move far from their original positions. 2. Make connections: The hypothesis describes how some materials flow. For example, consider the mudslide shown at left. Compared to point A, point B is nearly three times farther from where the mudslide landed at the bottom of the mountain. Why did the mudslide miss point A but hit point B?