Question

If jack was traveling at 100 miles in 2 hours what was his velocity in miles per second​

Answer 1

1 hour is 3600 seconds. In 2 hours, it would be 7200 seconds.  Divide the amount of miles by seconds. 100/7200=.01388..

Answer 2

We don't know anything about the direction Jack was traveling, so we can't determine his velocity.  The best we can do is work with his speed.

Speed = (distance covered) / (time to cover the distance)

Speed = (100 miles) / (2 hours)

Speed = 50 miles/hour

The question has specified a different unit, so we'll need to convert the unit of our answer.  

Let's multiply the answer by (1 hour / 3600 seconds).  The numerator and denominator of this fraction are both the same quantity, so the value of the fraction is ' 1 ', and multiplying the answer by it won't change the answer in any way except the unit.

Speed = (50 mi / hr) x (1 hr / 3600 sec)

Speed = (50mi · 1hr)  /  (hr · 3600sec)

Speed = 50 mi / 3600 sec

Speed = 0.01389 mi/sec