In each case when you start a simulation for the following questions, reset the values using the icon in the control panel at the left side of the screen. Each question assumes that you have done this. Then set only the values indicated in the question. 1. Turn off the lines on the simulation. Position the cursor at the origin. Notice that the cursor is equidistant from both centers, and the difference between distances is zero. Notice that the origin is a point where a wave crest from each center touches or intersects. Is this a point of constructive or destructive interference? 2. Move the cursor to the point (0,-4.3). Compared to the origin (in Item 1), this is the next point in the negative y-direction where two crests intersect. How far is the cursor from each center? What is the difference between the distances? Is this a point of constructive or destructive interference?3. Check some of the other wave crest intersections on the y-axis. Is the difference of distances to the cursor always zero? What kind of interference always occurs at these points?4. Check other points on the x-axis where wave crests from the two centers are tangent to each other. Is the difference of distances to the cursor always zero? What kind of interference occurs at these points?5. Can you find wave crest intersections that do not lie on either the x- or the y-axis for which the difference between the distances is still zero?6. Now move the cursor to the point(0,-8.7). What is the difference between the distances? Is this an area of constructive or destructive interference? Are wave crests or wave troughs interfering here? Notice that this point is equidistant from two wave crests from both the red center and the blue center.7. Areas of constructive interference appear as light bands or wedges, and areas of destructive interference appear as darker bands or wedges. Move the blue center so that it is at the same location as the red center. Do you see any areas of constructive or destructive interference? Slow drag the blue center along the x-axis away from the red center. Does the number of bands of constructive interference increase or decrease? From where do the bands appear to propagate?8. Notice that the wave crests from the two centers are in constructive interference on the x-axi:s (Item 4). Watching the display of path difference, slowly move the red center in the positive x- direction toward the blue center. What is the path difference when the wave crests from the red center (on the x-axis) are exactly halfway between the wave crests from the blue center? To what part of the wave from the blue center are the crests from the red center being added? What kind of interference is this?