A stationary source S generates circular outgoing waves on a lake. The wave speed is 4.0 m/s and the crest-to-crest distance is 80 cm. A boat is approaching the source at 1.0 m/s. The frequency of these waves, as observed by a person in the boat, is

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?

Adielectric-filled parallel-plate capacitor has plate area a = 30.0 cm2 , plate separation d = 9.00 mm and dielectric constant k = 3.00. the capacitor is connected to a battery that creates a constant voltage v = 15.0 v . throughout the problem, use ϵ0 = 8.85x10-12 c2/n. m2 . find the energy u1 of the dielectric-filled capacitor.

Which if these is an etiquette rule? (american football) question 10 options: a. debating with the ref over a call b. not communicating with your team c. post-game handshake d. taunting