Brad tries out a weight-loss plan that involves repeatedly lifting a 50.0 kg barbell from the floor over his head to a height of 2.0 m. If he is able to complete three such lifts per minute, how long will it take for him to lose 0.50 kg of fat? “Burning” 1 g of fat supplies 39 kJ to the body; of this, 10% can be used by the muscles to lift the barbell. (Ignore the fat “burned” while he lowers the barbell to the floor.)