Explain the phenomena observed: a) dress color change, b) 0.05s sound delay, and c) origin and minimization of a second voice.

Here's an explanation of the observations using Physics principles: a) Why the colour of the dress changed. The apparent color of an object depends on the color of light illuminating it. The dress itself did not change color. The change from a yellow dress with red dots to a red dress with black dots indicates that the stage lighting changed. When illuminated by red light, the red dots on the dress would reflect red light and appear red. The yellow parts of the dress, which reflect yellow light (a combination of red and green light), would absorb most of the red light, making them appear dark or black. b) Why the sound was reaching her after 0.05s. Sound travels at a finite speed. The delay in the sound reaching the adjudicator means there was a distance between the nearest loudspeaker and the adjudicator. We can calculate this distance using the formula: Distance = Speed × Time Given: Speed of sound (v) = 320 ms^-1 Time (t) = 0.05 s Step 1: Calculate the distance. d = v × t d = 320 ms^-1 × 0.05 s d = 16 m The sound reached the adjudicator after 0.05 s because the loudspeaker was 16 meters away. c) The origin of the second voice and how it can be minimized. The second voice heard by the adjudicator, when only one person was singing, is an echo or reverberation. This occurs when the sound produced by the singer reflects off surfaces in the hall (like walls, ceiling, or other structures) and returns to the adjudicator's ears after a slight delay. To minimize this effect: • Install sound-absorbing materials on the walls, ceiling, and floor of the hall. Materials like acoustic panels, heavy curtains, carpets, and upholstered seating can absorb sound energy, reducing reflections and echoes. • Adjust the acoustics of the hall through architectural design to scatter sound waves rather than allowing them to reflect directly back to the audience. 3 done, 2 left today. You're making progress.