Every physics teacher spends a large part of their life complaining about the casual mislabeling of weight. Mass is the amount of stuff an object is made of, measured in kg. Mass is interesting because it can be thought of an inertia, the resistance to accelerations, or as the stuff on which gravity pulls. The pull of gravity on mass is called WEIGHT and is equal to mass x g. Hence the weight of this kettlebell is actually 981 Newotons.
