(no subject)
This entry is physics C help/ a call for those who know more than me to correct my mistaken thinking. First, dot product.
Vectors A dot B = AB cos theta. This is what Irani said. This translates to |A||B|cos theta. In other words, AB stands for the magnitude of Vector A times the magnitude of Vector B. However, this can be simplified. the cosine theta disappears magically for a simple, yet easy to overlook reason. When we multiply the vectors, we split them into x and y (and z) components. Therefore, we are left with a long tedious expression I don't want to write. But thanks to the wonders of unit vectors, AB cos theta becomes AxBx + AyBy + AzBz. Much simpler. In my mind, anything without trig functions is simpler. Okay, so now I get dot product. Based on the book, I know that dot product is used to form a scalar value out of two vectors. That is why we are only concerened with magnitude, I guess. If you need to find the angle, you can always put that AxBx etc. equation = AB cos theta and solve from there. I think I get it. Now for cross product.
This I am having trouble with. Frankly, I need help. Let's see if my tutor can help over le phone. Or else I have some problems . . . :( I hate Irani.
Vectors A dot B = AB cos theta. This is what Irani said. This translates to |A||B|cos theta. In other words, AB stands for the magnitude of Vector A times the magnitude of Vector B. However, this can be simplified. the cosine theta disappears magically for a simple, yet easy to overlook reason. When we multiply the vectors, we split them into x and y (and z) components. Therefore, we are left with a long tedious expression I don't want to write. But thanks to the wonders of unit vectors, AB cos theta becomes AxBx + AyBy + AzBz. Much simpler. In my mind, anything without trig functions is simpler. Okay, so now I get dot product. Based on the book, I know that dot product is used to form a scalar value out of two vectors. That is why we are only concerened with magnitude, I guess. If you need to find the angle, you can always put that AxBx etc. equation = AB cos theta and solve from there. I think I get it. Now for cross product.
This I am having trouble with. Frankly, I need help. Let's see if my tutor can help over le phone. Or else I have some problems . . . :( I hate Irani.