Question

The speed of light is 1.86 × 105 miles/second. How far will light travel in 500 seconds? A. 9.3 × 105 miles B. 9.3 × 106 miles C. 9.3 × 107 miles D. 9.3 × 108 miles

Answer 1

Answer: Choice C, 9.3 x 10^7 miles

notes

* 9.3 x 10^7 is 93,000,000 or the number "93 million". This is the approximate distance from earth to the sun (I believe the average distance)

* 500 seconds = 8.333 min = 8 min, 20 seconds

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Work Shown:

speed of light is roughly 1.86 * 10^5 miles per second, assuming you meant to put an exponent between the 10 and 5. This means that in 1 second, light travels roughly 1.86*10^5 miles (about 186 thousand miles)

Multiply this by 500

500 * (1.86 * 10^5)

(500*1.86)*10^5

930 * 10^5

(9.3 * 10^2) * 10^5

9.3 * (10^2*10^5)

9.3 * 10^(2+5)

9.3 * 10^7

This is the same as 93,000,000 or "93 million" after you move the decimal point 7 spots to the right.