Answer:
9) 17 miles/hr
10) 7.14 miles
Explanation:
See the attached worksheet. Note the use of conversion factors. In question 9 we want to convert minutes to hours. We know there are 60 minutes/hr. So we can set up a conversion factor in one of 2 ways: (60 minutes/1 hr) or (1 hr/60 minutes). Both are valid, and both are = 1, since the numerator and denominator are both equivalent. This means we can invert a conversion factor and it is still = 1. Since conversion facots are equal to 1, we can multiply them times anything, and the result is numerically the same (anything times 1 = anything) and only the units have changed. For question 9, we want to convert miles/min to miles/hr. I'll choose the conversion factor (60 min/1 hr), mostly because I like multiplication over division. Note how the units cancel in the attachment, resulting in 17 miles/hr. One may also use the factor (1hr/60min), but then a division is required. Perfectly fine, but not my preferred route.
The same approach is used to answer question 10. Again, note how he units cancel, leaving a number wth just the units desired,