Question

The voyager 1 spacecraft is currently 20.7 billion km from earth and heading out of our solar system. how long does it take radio messages from voyager 1 to reach us

Answer 1

20.7 billion = 20.7E9 converting to units of 10

20.7E9 km = 20.7E12 m

t = S /v = 20.7E12 m / 3.0E8 m/s = 6.9E4 s = 69000 s

69000 s = 1150 min = 19.2 hrs