绳在竖直面内拉小球作圆周运动,拉力为什么做功,拉力不是与速度方向垂直吗?
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/19 06:34:25
![绳在竖直面内拉小球作圆周运动,拉力为什么做功,拉力不是与速度方向垂直吗?](/uploads/image/z/5028640-16-0.jpg?t=%E7%BB%B3%E5%9C%A8%E7%AB%96%E7%9B%B4%E9%9D%A2%E5%86%85%E6%8B%89%E5%B0%8F%E7%90%83%E4%BD%9C%E5%9C%86%E5%91%A8%E8%BF%90%E5%8A%A8%2C%E6%8B%89%E5%8A%9B%E4%B8%BA%E4%BB%80%E4%B9%88%E5%81%9A%E5%8A%9F%2C%E6%8B%89%E5%8A%9B%E4%B8%8D%E6%98%AF%E4%B8%8E%E9%80%9F%E5%BA%A6%E6%96%B9%E5%90%91%E5%9E%82%E7%9B%B4%E5%90%97%3F)
绳在竖直面内拉小球作圆周运动,拉力为什么做功,拉力不是与速度方向垂直吗?
绳在竖直面内拉小球作圆周运动,拉力为什么做功,拉力不是与速度方向垂直吗?
绳在竖直面内拉小球作圆周运动,拉力为什么做功,拉力不是与速度方向垂直吗?
对 就是因为拉力和速度垂直 所以不做功
将拉力分解到沿速度方向的分力,分力与速度同向,做正功。
小球要克服空气阻力,必须做功,那肯定就是拉力做功的,其实拉力与速度方向有一个接近90度的夹角 把拉力分解到沿速度方向的分力,分力就与速度同向,会做功
拉力不可能做功,只要是圆周远动。只要小球在无阻力的条件下,并且可以通过最高点,就能一直运动。拉力不做功
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全部展开
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收起
还存在重力,因为是匀速圆周运动,所以重力势能与拉力做的功发生转化