Andy has two samples of liquids. Sample A has a pH of 4, and sample B has a pH of 6. What can Andy conclude about these two samples?

Sample A is , and sample B is .

Because light travels in a straight line and casts a shadow, isaac newton hypothesized that light is

Abird flies directly overhead from where you stand at an altitude of 300.0 m and at a speed horizontal to the ground of 20.0 m/s. the bird has a mass of 2.0 kg. the radius vector to the bird makes an angle \thetaθ with respect to the ground. the radius vector to the bird and its momentum vector lie in the xyxy-plane. what is the bird’s angular momentum about the point where you are standing?

When using the scientist method, which step comes last?