Astronomers infer that the universe is expanding because distant galaxies all appear to ________
A) be made mostly of dark matter
B) be moving away from us, with more distant ones moving faster
C) rotate rapidly
D) be growing in size
B
You might also like to view...
Which of the following books of tabulated predicted planet positions was not based on uniform circular motion?
a. the Rudolphine Tables by Kepler b. the Prutenic Tables based on Copernicus' model c. the Alphonsine Tables based on Ptolemy's observations and calculations
Two campers wish to start a fire during the day. One camper is nearsighted and one is farsighted. Whose glasses should be used to focus the Sun's rays onto some paper to start the fire?
1.either camper’s 2.the nearsighted camper’s 3.the farsighted camper’s
A single slit, which is 0.050 mm wide, is illuminated by light of 550 nm wavelength. What is the angular separation between the first two minima on either side of the central maximum?
A) 0.36° B) 0.47° C) 0.54° D) 0.63° E) 0.73°
Four identical point charges (+4.0 ?C) are placed at the corners of a square which has 20-cm sides. How much work is required to assemble this charge arrangement starting with each of the charges a very large distance from any of the other charges?
a. +2.9 J b. +3.9 J c. +2.2 J d. +4.3 J e. +1.9 J