The planet neptune is, on average, about 4.5 billion km from the sun. how long does it take light from the sun to reach neptune? (recall that the speed of light is about 300,000 km/s)

It would take 15,000 seconds, or 250 minutes = 4 hours and 10 seconds.

Explanation:

In order to calculate the time it would take light from the sun to reach Neptune, we will make use of the given data, while noting that time = distance ÷ speed.

Given data:

distance = 4.5 billion km = 4,500,000,000 km (this is the distance between planet Neptune, and the sun).

speed = 300,000 km/s (this is the speed at which light travels).

Therefore, time = 4,500,000,000 ÷ 300,000 = 15,000 seconds = 250 minutes, or 4 hours and 10 seconds.