To calculate the masses of stars in a binary system, we must measure their ________
A) luminosities and distance from Earth B) orbital period and average orbital distance
C) absolute magnitudes and luminosities D) spectral types and distance from Earth
B
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An aquarium contains a 5-cm layer of water (n = 1.333) floating on top of carbon tetrachloride (n = 1.461). If the angle of incidence into the water from the carbon tetrachloride is 20°, what is the angle of refraction into the air?
a. 20° b. 30° c. 38° d. 69° e. 26°
Three materials with n1 < n2 < n3 are arranged in layers of uniform thickness. A light ray in air enters the first layer at an angle of incidence of 40° and the ray eventually exits the third layer at the refracted angle q in air. What is the value of q?
a. Some angle more than 40°. c. 40°. b. Insufficient information to answer. d. Some angle less than 40°.
What does the evidence that the Antarctic ozone hole has expanded over the past twenty years mean? Explain
What will be an ideal response?
In a baseball game, the catcher stops a 90-mph pitch. What can you say about the work done by the catcher on the ball?
a) catcher has done positive work b) catcher has done negative work c) catcher has done zero work