Question

1. if the speed of light is 3 x 108 meters/second, how many seconds does it take light to reach the earth, if the sun is 1.5 x 1011 meters from earth?

Explanation:

Step1: Recall the formula for time

The formula for time \(t\) is \(t=\frac{d}{v}\), where \(d\) is distance and \(v\) is velocity.

Step2: Substitute the given values

Here, \(d = 1.5\times10^{11}\) meters and \(v=3\times 10^{8}\) meters/second. So \(t=\frac{1.5\times 10^{11}}{3\times 10^{8}}\).

Step3: Simplify the expression

Using the rule of exponents \(\frac{a\times10^{m}}{b\times10^{n}}=\frac{a}{b}\times10^{m - n}\), we have \(\frac{1.5}{3}\times10^{11-8}\).
\(\frac{1.5}{3}=0.5\) and \(10^{11 - 8}=10^{3}\). So \(t = 0.5\times10^{3}=500\) seconds.

Answer:

\(500\) seconds