How do we determine the age of a star cluster?
a) by identifying the type of stars that have just turned off the main sequence
b) spectroscopic parallax
c) by determining the spectral types of the faintest stars in the cluster
d) radioactive dating
e) by comparing the ages of white dwarfs and red giants
Ans: a) by identifying the type of stars that have just turned off the main sequence
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The Sun and Moon both have an effect on the tides. Which one has the larger effect, and why?
A. The Sun, because its force differs more between the surface and center of the Earth B. The Moon, because its force differs more between the surface and center of the Earth C. The Moon, because it exerts a larger force on the ocean D. The Sun, because it exerts a larger force on the ocean E. Both the sun and Moon equally affect the tides
Which of the following aluminum alloys should you consider the primary candidate for a design where specific yield strength is the most critical design factor?
(a) 2024-T62 (b) 7075-T6 (c) 2090-T86 (d) 8090-T651
Most galaxies we see are moving away from us. How do we know this?
a) Light we receive from each galaxy has a longer wavelength than we expect. b) Each galaxy appears visibly smaller as time passes. c) We can see that the galaxies are getting dimmer from year to year. d) Light we receive from each galaxy has a shorter wavelength than we expect.
The center of gravity for each truck is marked X. Which truck(s) will tip over?
1) Truck 1 2) Truck 2 3) Truck 3 4) All will tip. This is because 5) its center of gravity is highest. 6) its center of gravity is lowest. 7) its center of gravity lies beyond a point of support. 8) all the centers of gravity lie above the wheelbases.