如何介绍杠杆这个物理概念第28周

以感性亲历的方式介绍杠杆这个物理概念。

Hello Ximalaya, this is Lindsay from New york! This week, nothing much happened. But, I’d like share with you an interesting science project.

大家好，我是晴川，今天LIndsay要介绍她科学课上的项目。中学生物化学物理都不细分，统一叫科学，明年八年级上的叫Earth Science，今年的科学课算物理项目下的，前一阵我们还介绍过有关摩擦力的碰撞实验。那么这一次是什么呢？

We had to build a catapult. A catapult is a type of lever, balancing on the fulcrum to lift a load. The fulcrum is a point in which the lever is stabilized on. The point of the project was for us to fully grasp the function of the lever, which is a type of simple machine.

Catapult 发射器  Fulcrum支点。Lever，杠杆。我这里配了一张图说明什么是发射器。大家看一下。中学物理实验课的时候会用到。

We were required to build a catapult with partners. Materials given to us were eight popsicle sticks, five rubber bands, a binder clip, and two straws.The goal is to create a catapult that was capable of launching 发射a rubber stopper to the ceiling 天花板.

Material, 这里是实验材料。Popsicle Stick就是冰棍儿的棍子，扁平的那种。Rubber Bands，皮筋儿，Binder Clip就是夹子，Straw吸管。Rubber Stopper是一个小小的橡皮，可以放在门背后，这样开门的时候不会碰坏门背后的墙，这个实验里是作为一个被发射的用具。

Well, my partner and I settled on a simple route. We stacked seven popsicle sticks together and then bound them together with a rubber band. The eighth stick, used as the lever, is propped against the stack, so one end was resting on the ground and the other would be in the air. It balanced on the stack so that it formed a cross if you looked down on it，the crossed point is served as fulcrum.

The rubber stopper would go on the end of the stick that touched the ground, then we’d slam down on the other end. It was simple and effective. We touched the ceiling once, which was pretty impressive. The people who won in every class competed against each other in the last championship. I didn’t win, but I didn’t mind, because I did well anyway.