How far does light travel in the following time spans: 4.0 days and 8.0 yr?

Question

From my notes I have that the speed of light is 2.997925 x 10^8. I need to figure out how to how it travels in the following time spans: 4.0 days, and 8.0 yr with the answers expressed using two significant figures. My calculations have been a little off and I am not sure what I am doing wrong, any explanation will be greatly appreciated. Thank you in advance!

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Answer 1 · 2018-04-12T21:43:11

$1.036*10^14 m$ and $7.563*10^16 m$

So we know the speed of light:

$2.997925*10^8 m/s$

Therefore we have to convert 4.0 days and 8.0 years to seconds:
For 4 days:
$4 days* 24 (hour)/(days) * 3600 (se cond)/(hour) =345600 se conds$

For 8 years:
Assuming one year is 365 days:
$8 years * 365 (days)/(years)* 24 (hour)/(days) * 3600 (se cond)/(hour) = 252288000$

Then we can calculate how far light has traveled in the period:

4 days:
$2.997925*10^8 m/s * 345600 s = 1.036*10^14 m$

for 8 years:
$2.997925*10^8 m/s * 252288000 s = 7.563*10^16 m$