Approximately how many days does it take for a massive star supernova to decline to 1% of its peak brightness?
A) 3 days
B) 30 days
C) 170 days
D) 300 days
D) 300 days
You might also like to view...
How do we know how old the solar system is?
A) by measuring the rate of the expansion of the universe B) We estimate the age based on how fast the terrestrial planets cooled and solidified. C) by radiometric dating of meteorites D) by measuring how much mass the Sun has lost through fusion over time
The shape and size of a nucleus can best be described as
A prankster drops a water balloon from the top of a building. If the balloon is traveling at 29.1 m/s when it strikes a window ledge that is 1.5 m above the ground, how tall is the building? Neglect air resistance
A) 45 m B) 43 m C) 46 m D) 47 m
An electron and a positron, which are two massive particles, can annihilate when they come together to produce two photons, which have no mass. This pair annihilation is an example of
a. time dilation b. length contraction c. the equivalence of mass and energy d. the principle of relativity e. none of the above