alexandracuhh alexandracuhh 08-10-2020 Physics contestada Your backpack has a mass of 8 kg. You lift it from the ground to a height of 0.7 m. How much work is done by gravity as you lift the backpack? A. -5.6 J B. 54.9 J C. -54.9 J D. 5.6 J Will mark brainliest!