The energy density of a battery is 200 Wh/kg200 \text{ Wh/kg}200 Wh/kg. What is this in MJ/kg\text{MJ/kg}MJ/kg?
0.72 MJ/kg0.72 \text{ MJ/kg}0.72 MJ/kg
7.2 MJ/kg7.2 \text{ MJ/kg}7.2 MJ/kg
72 MJ/kg72 \text{ MJ/kg}72 MJ/kg
0.072 MJ/kg0.072 \text{ MJ/kg}0.072 MJ/kg