Astronomers estimate that the universe has about 100 billions of galaxies, each of which has about 100 billions stars. Given there are so many stars in the Universe, why isn't our night sky completely filled with starlight?

All motion is caused by force? true or false

The atoms of a solid aluminum can are close together, vibrating in a rigid structure. if the can is warmed up on a hot plate, what happens to the atoms?

Acm ruler with main graduations from 1 to 10 from left to right there are 10 secondary graduations between each of the main graduations there is a line that begins. at the left end of the ruler 10 secondary graduations to the left of the “1 main graduation the right end of the line ends on the eighth secondary graduation to the right of 3 how long is the line