Question

The function d(t) equals 300,000t represents the distance (in kilometers) that light travels in t seconds. a) How far does light travel in 15 seconds? b) how long does it take light to travel 12 million kilometers?

Answer 1

Step 1:

In this question, we are given the following:

The function d(t) equals 300,000t represents the distance (in kilometers) that light travels in t seconds.

a) How far does light travel in 15 seconds?

`\begin{gathered} Given\text{ that:} \\ d\text{ = 300,000 t} \\ when\text{ t = 15 seconds, then we have that:} \\ d\text{ = 300, 000 x 15 } \\ d\text{ = 4, 500, 000 kilometers} \end{gathered}`

b) How long does it take light to travel 12 million kilometers?

`\begin{gathered} d\text{ = 300, 000 t} \\ when\text{ d = 12, 000, 000 kilometers, } \\ Then,\text{ we have that:} \\ 12,\text{ 000, 000 = 300,000 t} \\ Divide\text{ both sides by 300, 000, we have that:} \\ (12,000,000)/(300,000)\text{ = t} \\ \\ Then,\text{ t = 40 seconds} \\ \end{gathered}`