Which statement about a wave produced by a doorbell is true?
a. it does not require a medium to travel
b. it propagates in the form of compression and rarefactions
c. the particles of the wave medium vibrate perpendicular to the direction of the wave
d. it propagates through the crests and troughs

If angle "a" is 25°, angle "b" is: a) equal to angle c b) less than angle c c) greater than angle c

With the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 1.90

If you place a magnet under a clear dish, and sprinkle iron fillings over it, above what part of the magnet will most of the fillings gather