Timeline for How do you tell whether a force acting on an inclined plane is going up or down in its perpendicular component to the plane?
Current License: CC BY-SA 3.0
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| when toggle format | what | by | license | comment | |
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| Feb 17, 2016 at 16:23 | vote | accept | 83457 | ||
| Feb 16, 2016 at 15:43 | comment | added | mbeckish | By the way - you will do the same thing to gravity. You will make the original force of gravity the hypotenuse, and replace it with components parallel and perpendicular to the plane. This will show you how much gravity (the weight of the object) contributes to the normal force, and how much of the weight contributes to it accelerating down the plane. | |
| Feb 16, 2016 at 15:41 | comment | added | mbeckish | The advantage to the second technique is that the perpendicular forces have no effect on each other. So when calculating the normal force, you only have to look at the forces perpendicular to the plane, and can ignore the forces parallel to the plane. When calculating acceleration along the plane, you can ignore the perpendicular forces, and only look at the forces parallel to the plane. | |
| Feb 16, 2016 at 15:41 | comment | added | mbeckish | Physically, the meaning of the triangle is: You can remove the original force (the hypotenuse), replace it with the two perpendicular components, and the object won't know the difference - everything would behave exactly the same. So, when trying to calculate things like normal force and acceleration along the plane, you can either 1) just keep the original force as drawn, and use sine, cosine, etc. to try to calculate the normal force, etc., or 2) replace the original force with its parallel and perpendicular components, and then use them to reason about the normal force, etc. | |
| Feb 16, 2016 at 15:33 | comment | added | 83457 | I am not near a pen and paper right now, so could you briefly explain your reasoning behind this, and why it would work for every situation | |
| Feb 16, 2016 at 15:29 | history | answered | mbeckish | CC BY-SA 3.0 |