2=0.5*g*(T+0.15)^2-0.5*g*T^2=0.5g[(T+0.15)^2-T^2]=0.5g[(T+0.15)+T]*[(T+0.15)-T]=0.15g(2T+0.15)*0.15=0.0225g(2T+0.15)2T+0.15=2/孝好(0.0225g)T=[1/巧哪铅缓脊(0.0225g)]-0.075