The doppler effect is a change in the observed frequency if there is relative motion between
a. two sources
b. two observers
c. a source and an observer

Actual age your first developed of age well comparison age refers to absolute age true or false

Which set of characteristics best describes sedimentary rock? a) largest type of rock, made of organic matter, hardest type of rock b) often contains layers, forms near sources of water, contains fossils c) least abundant type of rock, made of other rocks, made mostly of minerals d) most abundant type in earth's crust, made of magma/lava, contains no fossils

Which of the following types of stars are dim but can have high surface temperatures? giants main sequence stars supergiants dwarfs