depress 爱问知识人

问：弹簧受力a spiral spring with a spring constant k=200N/m rests on a horizontal surface with its axis vertical. How much work must be done to depress the top of the spring a distance of 10 cm? Having depressed the spring as described a mass of 0.2 kg is placed on top of it. If the spring is suddenly released so it can expand, how far into the air will the mass be propelled?

答：1）有公式 w=k*L^2/2 其中 L为长度的变化量 w为弹簧弹性势能变化量 有能量守恒原理 （功能定理）有 做功=弹簧弹性势能的改变 所以 做功 w=0....详情>>