# Light travel through space at a constant speed of about 3×10^5km/s earth is about 1.5×10^8km from the sun how long does it take for light from the sun to reach earth?

Apr 14, 2018

500 seconds

#### Explanation:

Divide the distance by the speed to find the time

$\frac{1.5 \times {10}^{8}}{3 \times {10}^{5}}$ =$0.5 \times {10}^{3}$=500 secs

If you struggle with scientific notation

$\frac{150 , 000 , 000}{300 , 000}$=$\frac{1500}{3}$=500

Apr 14, 2018

$\text{Time"= 500" s}$

#### Explanation:

Starting with the equation:

$\text{Distance" = "Speed" xx "Time}$

We shall solve the equation for $\text{Time}$ in terms of $\text{Distance}$ and $\text{Speed}$:

$\text{Time"= "Distance"/"Speed}$

Substitute $\text{Distance" = 1.5xx10^8" km}$ and $\text{Speed" = 3xx10^5" km/s}$

"Time"= (1.5xx10^8" km")/(3xx10^5" km/s")

$\text{Time"= 500" s}$

Apr 14, 2018

500 Seconds

#### Explanation:

Distance = Speed x Time
Time = Distance/Speed
$t = \frac{1.5 \cdot {10}^{8}}{3 \cdot {10}^{5}}$
$t = \frac{{10}^{3}}{2}$
$t = 500$ Seconds