What happens when an unstoppable force meets an immovable object?
You may not like the answer. But here it is, this question doesn’t make sense. It stems from two contradicting axioms (statements taken to be true by definition) which nullify whatever result we derive from them.
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An easy way to understand and draw and free-body diagrams for beginners (with worked examples).
Two of the most ancient and fundamental concepts in physics are still widely misunderstood and confused today.
The term ‘normal force’ might be misleading to some, especially those without a background in mathematics. It may seem to suggest that the force in the question is straightforward, ordinary,…
You may have heard or read the following statements in relation to centrifugal force and centripetal force:
“Centrifugal force isn’t a real force.”
“It depends on the frame of reference.”
“They both act on the same body but in opposite directions.”
To be clear, only one of the three statements above is correct. This goes to show that there is quite a bit of confusion and misunderstanding between the two concepts. Hopefully, this article will clear up some of the air so that by the end of it, one can clearly and accurately distinguish the two.
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Do we really need “linear momentum”? Can’t we just find a way to study motion with velocity, inertia, force, or energy? Why bring more jargon into what is already a confusing mess of terminologies and equations?
To a beginner, the concept of momentum can be a difficult thing to grasp and sometimes confusing. For example, momentum is a vector quantity, meaning it is a quantity that has magnitude as well as direction in space. This alone brings in a cascade of problems when solving questions because both have to be taken into account. And then comes along the concept of “conservation of momentum”, which is like spilling gasoline on the confusion fire. It doesn’t help that physics teachers love to mess around with these ideas as they lay traps and snares into their student’s exams.
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I don’t know where you are as you are reading this. You could be sitting on a bus, in your room, at a cafe, in a park, or even lying on your bed. Whenever you may be, I am sure if you look around or listen carefully to your environment, you will note some hints of motion. Perhaps a bug buzzing around, a sound of a passing car, birds singing outside, a distant siren, or a screech of a chair. In any case, I can guarantee there is motion all around you.
But for the sake of this article, let us suppose that you are reading this from deep space, so deep that when you lift up your eyes to look around through the glass helmet of your spacesuit, all you see is pitch darkness. No stars or light of any kind; not a single dot in the bare dark sky.
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The two quantities are different than you think
Force is casually defined in physics as a push or a pull. The effects of an applied force are obvious: to cause motion, to stop motion, and to deform an object. Torque is a special name given to a force that causes things to turn, twist, or bend. Such as when you are turning the steering wheel of your car. It would be weird – wouldn’t it, to say that you are pulling the steering wheel of your car to the right instead of turning the steering wheel. It gives an impression of someone trying to rip off the steering wheel, and nobody wants that! “Turn” is the word, and “Torque” is the technical word for it. In fact, the word “Torque” has its origins in the Latin language where it means to “twist” or “turn”.
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Has it ever occurred to you that the universe behaves in a systematic, profound, orderly way? It’s as if it subconsciously follows a hidden set of rules, privy to none other than itself. It becomes the job of the scientist then, to probe into nature and try find these little nuggets of truth. To accomplish this, a scientist makes observations, conducts experiments, and uses perhaps the greatest probing tool ever: mathematics. When scientists do discover these hidden truths of the universe they hand out names such as laws, principles, theorems, theories, etc. to these general behaviors of the universe. We get terms such “laws of physics”.
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