This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Mechanical Waves Prelab Figure 1: The Shive Wave Machine 1 Reflected Pulse A wave pulse with positive amplitude A travels from the origin in the + x direction and meets an unclamped end of the Shive Wave Machine, figure 1. Will there be a reflected wave pulse? Will the amplitude of the reflected pulse be positive or negative? Read section 14.6 (page 232) in your textbook. The incoming wave is travelling in the + x direction. If there is a reflected wave pulse, it will be travel in the opposite direction, i.e. in the- x direction. The words ’positive’ and ’negative’ in this question do not refer to the direction in which the wave pulse is travelling. Instead, they refer to the sign of the amplitude of the pulse. The clamped end of the wave machine represents a fixed boundary. The key question is, when a wave pulse hits a fixed boundary will the amplitude of the reflected wave be 1 inverted with respect to the incoming wave? Or will the amplitude of the reflected wave be upright with respect to the incoming wave? I have defined the incoming wave pulse to have a positive amplitude. If the reflected pulse is inverted, it will thus have a negative amplitude. If the reflected pulse is upright with respect to the incoming pulse, then it will have a positive amplitude. You should tell me which of these two cases will occur at a fixed boundary. Food for thought: We will work with two types of boundaries, fixed and free. You have just described what happens to the reflected wave pulse at the fixed boundary. What happens to the wave pulse when the boundary is instead free to oscillate?...
View Full Document
This document was uploaded on 05/08/2011.
- Fall '09