One of the nearest stars is Alpha Centauri,whose distance is 4.2 × 10¹⁶ m.How long does it take light to travel from Alpha Centauri to us? A)1.25 seconds B)8.3 minutes C)4.4 years D)560 years E)6,200 years

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Quizplus · Accepted Answer

We can use the formula d=vt, where d is the distance, v is the speed of light and t is the time taken. Rearranging this formula, we get t=d/v. 
Plugging in the values, we get t=(4.2 x 10^16 m) / (3 x 10^8 m/s) = 14,000 seconds. 
Converting this to years, we get t=14,000 sec x (1 min/60 sec) x (1 hour/60 min) x (1 day/24 hours) x (1 year/365.25 days) = 4.4 years. Therefore, the answer is C.

One of the Nearest Stars Is Alpha Centauri,whose Distance Is