Which are ways to improve the design of this experiment? Check all that apply.
Record data only at the very end to save time.
Experiment with a wider range of materials.
Use more legible handwriting when recording data.
Use a laboratory galvanometer to make precise measurements.
Test the strength of the electromagnet by varying the number of wire coils.

The star betelgeuse is about 600 light-years away. if it explodes tonight, a. we'll know because debris from the explosion will rain down on us from space.b. we'll know it immediately because it will be brighter than the full moon in the sky.c. we won't know about it until 600 years from now.d. none of the above.

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

Ionic compounds can be readily dissolved in water because the high dielectric constant of water screens and decreases the force between the oppositely charged ions.