30 kg30 \mathrm{~kg}30 kg
150 kg150 \mathrm{~kg}150 kg
3.6×103 kg3.6 \times 10^{3} \mathrm{~kg}3.6×103 kg
7.5×103 kg7.5 \times 10^{3} \mathrm{~kg}7.5×103 kg