A metal bar is in the xy-plane with one end of the bar at the ori...

Question

A metal bar is in the xy-plane with one end of the bar at the origin. A force F = 97.00 N)i + (-3.00 N)j is applied to the bar at the point x = 3.00 m, y = 4.00 m. (a) In terms of unit vectors i and j, what is the position vector r for the point where the force is applied?

Accepted Answer

welcome back everybody. We are looking at a wrench in a wheel nut from a top down view in the X. D. Planes. I'm actually gonna draw out our XZ plane right now. Here is our X. And we have ours just like that And let me label it such at the origin is our nut. And we have our wrench exerting a force to this nut. Now we are told at the point negative one in 10.25 -1 in the X. direction. .25 in direction. We have some force given by this equation right here. So it looks like in the extraction is a little bit bigger. So our forces gonna look something like this. And we are asked to find what the position vector is from the origin to the point of our application of our force. So find our well our is going to have the form of some X. Value in the times ri unit. So along the X axis essentially plus some Z coordinate. I'm our K. Unit vector which means to direction. Well for this X and z we can actually just use the point of application coordinates. So let's go ahead and plug those in. We have that our position vector is equal to negative one times our I unit vector plus 0.25 times our K. Unit vector. I just want to point this out here. Although we were given this force. This was just a red herring here. We didn't have to use that at all to find our position vector of native one. I plus 10.25 K, corresponding to our final answer choice of D. Thank you guys so much for watching. I hope this video helped. We will see you all in the next one.

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