How are physical properties used to classify stars

Astudent observes a star from two positions of earth in its orbit, in summer and winter, and measures the change in the position of the star. which of these can be best calculated by this method?

Which of the following types of stars is most likely to end up as a supernova? in graph a, the curve peaks at 800 nm, in the red section of the visible light spectrum. in graph b, the curve peaks at 550 nm, in the green section of the visible light spectrum. in graph c, the curve peaks at 450 nm, in the blue section of the visible light spectrum. in graph d, the curve peaks at 300 nm, in the violet section of the visible light spectrum. a b c d

Cpr, or cardiopulmonary resuscitation, is a first-aid technique to save lives. it involves compressions of the patient's chest cavity. which description is the best description of the functions of chest compressions in cpr? chest compressions are done to pump the heart. chest compressions are done to strengthen the rib bones. chest compressions increase carbon dioxide inhalation. chest compressions allow the patient's muscles to wake up.