
根据胡克定律,有F(x)=kx每压缩1cm需力5N,即F(0.01)=0.01k=5k=500弹簧原长为1m,将其从80cm压缩至60cm,压缩量从0.2m增加到0.4m,所做的功为W=∫[0.2,0.4]500xdx=250x²|[0.2,0.4]=250(0.4²-0.2²)=30(J)

根据胡克定律,有F(x)=kx每压缩1cm需力5N,即F(0.01)=0.01k=5k=500弹簧原长为1m,将其从80cm压缩至60cm,压缩量从0.2m增加到0.4m,所做的功为W=∫[0.2,0.4]500xdx=250x²|[0.2,0.4]=250(0.4²-0.2²)=30(J)