Arunner wants to run 12.3 km . she knows that her running pace is 6.8 mi/h.
how many minutes must she run? hint: use 6.8 mi/h as a conversion factor between distance and time.

To answer this question, you need to know how to convert mile into kilometer. One mile is equal to 1.60934km. Then the runner speed in km/h should be: 6.8 mi/h * 1.60934km/mi= 10.94km/h.
Then the time needed should be:
time= distance / velocity= 12.3km / (10.94km/h)= 1.1243 hour *60 minute/hour= 67.45minutes

Mass is the amount of matter in an object.  weight is the measurement of the pull of gravity on an object.  say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165)  now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon.  however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant.  in conclusion it is possible for your weight to change as your mass remains constant.