Which is characteristic of globular star clusters?
A) a mix of old and young stars, about 100,000 ly across
B) old age and hundreds of thousands of stars, only about 30 ly wide
C) bright blue main sequence stars, and thousands of them
D) only brown dwarfs in a yellow ball 100 ly across
E) no remaining main sequence stars, but millions of white dwarfs
B
You might also like to view...
A steam generator is a device that converts water into steam by capturing radiant heat from hot gases. Consider a 15 foot cubed steam generator, all sides made up of water tubes and a “fire ball” 6 ft. in diameter at 4000ºF at the center. If the water tubes have a surface temperature of 600ºF and an emissivity of 0.7, determine the heat transfer to the water from the combustion gases. Assume the fire ball acts as a black body.
What will be an ideal response?
When a mass of 0.350 kg is attached to a vertical spring and lowered slowly, the spring stretches a distance d. The mass is now displaced from its equilibrium position and undergoes 100 oscillations in 48.9 s. What is the stretch distance d?
A) 2.35 cm B) 2.97 cm C) 4.71 cm D) 5.94 cm E) 6.28 cm
Power: What is the net power needed to change the speed of a 1600-kg sport utility vehicle from 15.0 m/s to 40.0 m/s in 4.00 seconds?
A. 100 kW B. 10.0 kW C. 140 kW D. 14.0 kW E. 275 kW
Compared to the speed of a 400 Hz sound, the speed of a 200 Hz sound through air is
A. twice as great. B. the same. C. one half as great. D. none of these answers are correct