The periodic wave in the diagram below has a frequency of 40 hertz. What is the speed of the wave?

answers:
A. 120 m/s
B. 60 m/s
C. 27 m/s
D. 13 m/s

What is the fate of the electrons that interact with a specimen in an electron microscope?

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?

What sort of waves exhibit the doppler effect?