Stellar spectra started with the amount of hydrogen found in the star's spectrum and started with the letters A through Q. What are the current letters used to classify stellar spectra?
What will be an ideal response?
OBAFGKM
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What method does "stars that fade" refer to?
A: Transits B: Radial velocity C: Astrometry D: Microlensing E: Direct imaging
A baseball leaves the bat with a speed of 47 m/s and an angle of 45° above the horizontal. A 5.0-m-high fence is located at a horizontal distance of 137 m from the point where the ball is struck. Assuming the ball leaves the bat 1.0 m above ground level, by how much does the ball clear the fence?
a. 59.7 m b. 47.7 m c. 49.7 m d. 121 m
Electromagnetic waves of all wavelengths are collectively known as ________.
A. the electromagnetic spectrum B. the visible spectrum C. blackbody radiation D. white light E. a continuous spectrum
Bottles of perfume sometimes have thick glass (n = 1.5) walls which give the impression the volume is larger than it really is. Assume a cylindrical bottle with an inner radius of 1.0 cm and an outer radius of 2.0 cm. What percentage of the apparent volume is the real volume?
a. 95% b. 60% c. 80% d. 64% e. 75%