The closest star to our sun, proxima centauri, is 39,900,000,000,000,000
meters away from earth.
a. write this distance in scientific notation. 3.90 * 10
b. light travels at a speed of 3.0 * 108 meters per second. how can you
calculate the time in seconds that it takes light from proxima centauri
to reach earth? how many seconds does it take? write your answer in
scientific notation and standard notation.