The period from about 100 seconds up to 15 minutes after the Big Bang is the:
A) Radiation Era.
B) Lepton Epoch.
C) Nuclear Epoch.
D) Decoupling Epoch.
E) Matter Era.
C
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The Doppler effect is sensitive only to motion along the line of sight
Indicate whether the statement is true or false
What do moonquakes reveal about the Moon?
A) It has a strong magnetic field generated by a large molten core. B) It has a differentiated core, displaced away from us by the Moon's rotation. C) Its small, partially molten core has been pulled toward us by tidal forces. D) The Moon has been geologically dead throughout its entire history. E) The Moon is quite active, almost as much so as Jupiter's moon Io.
The moons of Mars, Phobos (Fear) and Deimos (Terror), are very close to the planet compared to Earth's Moon
Their orbital radii are 9,378 km and 23,459 km respectively. What is the ratio of the period of revolution of Phobos to that of Deimos? A) 0.2528 B) 0.3998 C) 1.582 D) 2.858 E) 3.956
The object in a ray diagram is perpendicular to the principal axis but does not have one end lying on the principal axis. The minimum number of rays that must be drawn in this ray diagram in order to determine the position of the image is
a. 1. b. 2. c. 3. d. 4. e. 5.