Question

How long does it take (in minutes) for light to reach venus from the sun, a distance of 1.152 × 108 km?

Answer 1

Using the precise speed of light in a vacuum ($299,792,458 \ \frac{m}{s}$), and your given distance of $1.152 * 10^{8} km$, we can convert and cancel units to find the answer. The distance in m, using $\frac{1000 \ m}{1 \ km}$, is $1.152 * 10^{11} m$. Next, for the speed of light, we convert from s to min, using $\frac{1 \ min}{60 \ s}$, so we divide the speed of light by 60. Finally, dividing the distance between the Sun and Venus by the speed of light in km per min, we find that it is 6.405 min.