机械能热能互变演示器用于演示热能和机械能的互相转变，说明克服摩擦力做功可以产生热，消耗热也可以做功。
J2254 Mechanical Energy Can Demonstrate Cross-Change
Mechanical energy can change each presentation is used to demonstrate the mechanical and thermal changes in each other, to overcome the friction that can arise when working heat, heat consumption can also be acting.