gavianacandelar3626 gavianacandelar3626 10-10-2022 Physics Answered Determine how many helium-filled balloons will be needed to lift a person whose mass is 70 kg. the air density is pair = 1.20 kg/m3 , the helium density is phe = 0.17 kg/m3, and the balloon's volume is vm = 30 liters.