A)convex lens is plac monochromatic red light. when viewed from above, concentric bands of red and dark are observed. what does one observe at the exact center of the lens where the lens and the glass plate are in direct contact? a) a bright red spot b) a dark spot c) a rainbow of color convex lens is placed on a flat glass plate and illuminated from above with d) a bright spot that is some color other than red b

Wo audio speakers are placed on a vertical rail. speaker a is placed at head-level while speaker b is place at some variable height, \delta yδy, above speaker a. both speakers receive simultaneous input from a sine-wave generator so the speakers each produce a pure sinusoidal sound wave with a wavelength of 0.531 meters. calculate the lowest height that speaker b can be placed above speaker a to produce a minimum of sound heard by person standing \delta x = 7.86δx=7.86 meters directly in front of speaker a.

Aray of light traveling parallel to the principal axis of a concave mirror will be reflected through the mirror's

The passage that directs air to the lungs is called a. diaphragm. b. larynx. c. bronchi. d. pharynx.