The discussion centers on the application of Newton's Third Law to explain why an individual cannot lift themselves by pulling on their shoelaces. Participants clarify that the forces involved—one acting on the shoelaces and the other on the person—do not cancel each other out because they act on different objects. The key takeaway is that action-reaction pairs cannot produce a net force of zero when they act on separate entities, thus preventing self-lifting through this method.
PREREQUISITESStudents of physics, educators teaching Newtonian mechanics, and anyone interested in understanding the principles of force and motion in everyday situations.
astrololo said:Homework Statement
I need to explain why I can't lift myself by pulling my shoes' laces.
The Attempt at a Solution
My explanation is that by pulling on your laces, there is always going to be a force that goes against your force, so this is why you can't pull yourself up. (So we're using NEwton's third as an explanation) Is this correct ?[/B]
Sorry, I didn't phrase correctly what I meant. But is what you wrote the explanation for why I cna't pull myself ?Mister T said:No this is not correct. Let me rephrase your answer in a way that might help you see this.
You pull up on your laces, your laces pull down on you. One of these two forces (they're an action/reaction pair) is on your shoe laces. The other is on you. Since the forces act on different objects, they can't cancel each other out. For two forces to be able to cancel each other they would need to act on the same object.
astrololo said:Sorry, I didn't phrase correctly what I meant. But is what you wrote the explanation for why I cna't pull myself ?