When we measure the broadening of absorption lines in the spectrum of an elliptical galaxy, we can infer
A) how quickly the galaxy is forming new stars.
B) how fast the stars in the galaxy are moving relative to one another.
C) the galaxy's rotation curve.
D) the amount of gas and dust in the galaxy.
E) the mass of the black hole at the galaxy's center.
B
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A rescue plane flying horizontally at 72.6 m/s spots a survivor in the ocean 182 m directly below and releases an emergency kit with a parachute. Because of the shape of the parachute, it experiences insignificant horizontal air resistance
If the kit descends with a constant vertical acceleration of 5.82 m/s2, how far away from the survivor will it hit the waves? A) 574 m B) 4.54 km C) 406 m D) 602 m
A certain coin has a diameter of 21.21 mm, a thickness of 1.95 mm, and weighs 0.04905 N. What is its density?
A) 29.1 × 103 kg/m3 B) 7.26 × 103 kg/m3 C) 9.25 × 103 kg/m3 D) 2.31 × 103 kg/m3 E) 71.2 × 103 kg/m3
An automobile traveling along a straight road increases its speed from 30.0 m/s to 50.0 m/s in a distance of 180 m. If the acceleration is constant, how much time elapses while the auto moves this distance?
a. 6.00 s b. 4.50 s c. 3.60 s d. 4.00 s e. 9.00 s
Which of the following mathematical expressions should be used to calculate the momentum of an auto?
A. mass × velocity B. weight × speed C. weight × force D. mass × acceleration