
解:∵p=m/v,且p铁=7.8×103Kg/m3,m=150g=0.15kg∴v铁=m/p=0.15kg/7.8×103Kg/m3=0.00001923kg=0.01923 m3又∵细铁丝的直径是1mm∴铁丝的横截面积为s=∏r2=3.14×(1/1000)=3.14×10-3m2∴铁丝的长度为L= v铁/s=0.01923 m3/3.14×10-3m2=6..124m因此这团铁丝约有6.124米长

解:∵p=m/v,且p铁=7.8×103Kg/m3,m=150g=0.15kg∴v铁=m/p=0.15kg/7.8×103Kg/m3=0.00001923kg=0.01923 m3又∵细铁丝的直径是1mm∴铁丝的横截面积为s=∏r2=3.14×(1/1000)=3.14×10-3m2∴铁丝的长度为L= v铁/s=0.01923 m3/3.14×10-3m2=6..124m因此这团铁丝约有6.124米长