Question

The speed of light is about 186,000 mi/s. Use the information in Exercise 88(a) to find how long it takes for a light ray from the sun to reach the earth.

Short answer

It will take 500 seconds.

Step-by-step solution

Step 1. Scientific Notation.

A positive number x is said to be written in scientific notation if it is expressed as follows:

$x=a\times {10}^n\text{where}1\le a<10$ and n is an integer.

We know that$\text{Time}=\frac{\text{distance}}{\text{speed}}$

Step 2. Determine the expression.

It is given that the distance from the Earth to the Sun is about 93 million miles or 93,000,000 miles.

Also, the speed of light is 186,000 miles/second.

The required expression is:$\text{Time}=\frac{93,000,000}{186,000}$

Step 3. Simplify the expression.

$\frac{93,000,000}{186,000}=500$

Hence, it will take 500 seconds.