初中物理习题中有这样的一个题目:请你用下列器材制作一个简易的测力计,并用它来研究物体的重力与质量的关系,写出研究方案.使用器材包括橡皮筋、小塑料瓶盖、硬纸板、细线、图钉、等大的自行车钢珠若干.要完成这题,首先要制作橡皮筋测力计,然后根据所制作的测力计研究等质量的 The junior high school physics problem has such a topic: Please use the following equipment to make a simple dynamometer, and use it to study the relationship between the gravity and the quality of objects, write a research program. The use of equipment including rubber bands, small plastic bottle caps , cardboard, thin lines, pushpins, and other large bicycle balls. To complete this, first make a rubber band dynamometer, and then study the quality of the