The first one is A and the second one would be C
Answer:
A) 15.0 years
Explanation:
Due to the distance to the star system is in light-year units, we can compute the time by using:

then, Rob will take to complete the trip about 15 light-years.
hope this helps!!
A sound wave<span> in a steel rail </span>has<span> a </span>frequency of<span> 620 </span>Hz<span> and a </span>wavelength<span> of 10.5 ... Find the </span>speed<span> of </span>a wave<span> with a </span>wavelength of 5<span> m and a </span>frequency of<span> 68 </span>Hz<span>.</span>
Answer:
What were the most important reasons that the Civil War started?
Explanation: i got it correct