A train passes by you and moves away at a speed of 26.8m/s. If its airhorn produces a pitch of 555Hz, what pitch do you hear? a: f= 602Hz
b: f=528Hz
c: f=582Hz
d: f=515Hz

Phase changes are chemical changes. true or false

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

1. when conducting a test on what kind of music increases the growth of plants, all of the following would fail to meet to fair test standard except (1 point) using different kinds of plants. giving some plants more water than others. exposing the plants to different types of music. using nutrient-rich soil for one and lesser soil for others. 2. engineering uses scientific thinking to solve real-world problems. (1 point) true false 3. what does it mean to test a hypothesis? (1 point) pass a quiz on other scientists’ results analyze only the results from scientific sources not make assumptions about how an experiment will turn out see if the results of an experiment are what the scientist predicted