How much heat is required to change the temperature of a 15 g aluminum can with 100 g of water from 24.5°c to 55°c?

Heat capacity of aluminium = 0.900 J/g°C
While heat capacity of water = 4.186 J/g°C
Heat = heat gained by water + heat gained by aluminium 
Heat gained by water = 100 × 4.186 × 30.5 
                                   = 12767.3 Joules
Heat gained by aluminium = 15 × 0.9 × 30.5 
                                          = 411.75 Joules
Heat required = 13179.05 Joules or 13.179 kJoules

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.