Detailed study of stellar spectra in 1897, which enabled the development of the H-R diagram, was performed by:
A) E.C. Pickering.
B) Harlow Shapley.
C) James Lick.
D) John Herschel.
E) Antonia Maury.
E
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A small bomb, of mass 10. kg, is moving toward the North with a velocity of 5.0 m/s. It explodes into three fragments:
a 5.0 kg fragment moving West with a speed of 8.0 m/s; a 4.0 kg fragment moving East with a speed of 10. m/s; and a third fragment with a mass of 1.0 kg. What is the velocity of the third fragment? (Neglect air friction.) A) 40 m/s North B) 5.0 m/s South C) 50.m/s North D) zero E) 4.0 m/s North
Two cars are traveling at the same speed and hit the brakes at the same time. Car A decelerates (decreases its velocity) at twice the rate of car B. If car A travels a distance D before stopping, how far does car B travel before stopping?
A) 4D B) 2D C) D D) D/2 E) D/4
How much current must pass through a 400-turn ideal solenoid that is 4.0 cm long to generate a 1.0-T magnetic field at the center? (?0 = 4? × 10-7 T ? m/A)
A) 80 A B) 22 A C) 13 A D) 0.013 A E) 40 A
A vibrating diatomic molecule in its ground state has energy E. What is the energy of the same molecule in its second EXCITED state?
A) 2E B) 3E C) 9E D) E E) 5E