字幕列表 影片播放 列印英文字幕 Smart Learning for All Topic: Balanced and Unbalanced Forces. How are we able to stand on the earth without falling into the center of the earth? That was a nice balancing act. Do you know there are certain forces around us which keep us balanced or unbalanced? Force is a push or a pull exerted on an object. Every object on the earth experiences various forces. When a number of forces acting on an object are such that their resultant force is zero. Then the forces are said to be balanced. Whereas, when a number of forces acting on an object are such that their resultant force is not equal to zero. Then the forces are said to be unbalanced. When he was falling which forces were acting on him? Were they balanced or unbalanced? In this case, unbalanced forces were acting on him. On earth, many forces act on an object. One of them is gravitational force of the earth. Gravitational force of the earth is the force which pulls all the objects downwards. Towards the center of the earth. Let's get back to the question. When he was falling, the gravitational force over powered all other forces. So, the resultant force was not equal to zero. Hence, we can conclude that unbalanced forces were acting on him. Did you see that? He landed safely. But if the gravitational force was pulling him towards the center of the earth. Why did he fall on the ground and not into the center of the earth? We know that gravitational force is pulling us downwards. However, there is another force exerted by the ground which pushes us upwards. This force is called the normal force. It is equal to the gravitational force. Normal force is exerted by a surface only when we are in contact with it. Since these two forces acting on us are equal but opposite to each other, their resultant. Net force is zero. Thus, these balanced forces keep us from falling into the center of the earth. For more educational videos please visit http://www.SmartLearningforAll.com Also, don't forget to subscribe to our YouTube channel.
A2 初級 美國腔 為什麼我們不掉進地球中心?| 我的天啊!我的天啊!我的天啊!我的天啊!我的天啊!我的天啊 (Why dont we fall into the center of the earth? | #aumsum) 17 1 AumSum 發佈於 2021 年 01 月 14 日 更多分享 分享 收藏 回報 影片單字