A frame-by-frame analysis of a slow-motion video shows that a hovering dragonfly takes 7 frames to complete one wing beat. If the video is shot at 240 frames per second, (a) what is the period of the wing beat, and (b) how many wing beats does the dragonfly perform per second?

Bradley was working in the lab. he accidentally poured a container of concentrated hydrochloric acid into his container of distilled water. not thinking much of it, he continued with his work as if nothing happened. which of these would be the result of this laboratory accident? a) the water will change to a bright pink color. b) the new solution would decrease in temperature. c) the solution has now become a good conductor of electricity. d) hcl and water have the same chemical and physical properties, so nothing would happen.