Astudent weighing 120 lbs climbs a 12 ft flight of stairs in 9 seconds. how much power did the student create?

Power can be calculate through the equation,
                        Power = Force x velocity

It should be noted that velocity is calculated by dividing displacement by time. Thus, from the given in this item we can calculate for the power. 
                       Power = (120 lb) x (12 ft/9 s)
                          Power   = 160 lb.ft/s

100kg

Explanation:

His mass on the moon and the earth will be the same.

  Weight = mass x acceleration due to gravity

  Acceleration due to gravity  = 9.8m/s²

Let us find the mass;

       Weight on earth  = 980N

       Mass  = ?

     

Insert the parameters and solve;

         980  = mass x 9.8

              mass =   = 100kg