The wavelengths corresponding to the harmonics of an organ pipe that is open at one end and closed at the other can be found by saying that the length of the pipe must be equal to:
a. an integer number of wavelengths.
b. an odd number of half-wavelengths.
c. an integer number of half-wavelengths.
d. an odd number of quarter-wavelengths.

Laboratory experiments, observational field studies, and model-building are all examples of different forms of scientific investigations.  in what way do laboratory experiments primarily differ from other forms of scientific investigations?   a.  a laboratory experiment is the only accepted form of investigation within the scientific community.  b.  studies about how things behave in nature or studies involving very large objects are best answered through laboratory experiments.  c.  laboratory experiments involve the identification and control of variables.  d.  data can only be generated through laboratory experiments, not other forms of investigation.

What is the most useful equation for electric power?

In a simplified model of the human eye, the aqueous and vitreous humors and the lens all have a refractive index of 1.40, and all the refraction occurs at the cornea, whose vertex is 2.60 cm from the retina. what should be the radius of curvature of the cornea such that the image of an object 40.0 cm from the cornea’s vertex is focused on the retina?