Author Question: Work done within an isolated system can increase the energy of the system. Indicate whether the ... (Read 98 times)

fbq8i · **on:** Jul 28, 2018

Work done within an isolated system can increase the energy of the system.
Indicate whether the statement is true or false

Question 2

About how old was the universe when the microwave background radiation that Penzias and Wilson discovered first became visible?
a. 1 microsecond (10-6 second) when the electromagnetic force separated out from the electroweak force.
b. 3 minutes, the start of the period that ended with typical photons unable to produce electron-positron pairs.
c. 300 thousand years, when matter in the universe became transparent to photons.
d. 1 million years, when the strong force separated out.
e. 30 million years, when the strong force separated out.