Saved Bookmarks
| 1. |
If A = (6i-8j) units, B = (-8i-3j) units, and C = (26i-19j) units, determine a and b such that aA + bB + C = 0 ( |
|
Answer» aA+bB+c = 0 then a =? b= ?assuming that is the vector sum has to be zero...x,y components have to ADD to zerox:a(6) + b(8) + 26 = 0y:a(–8) + b(3) + 19 = 0two equations, 2 unknowns6a + 8b + 26 = 0–8a + 3B + 19 = 03a + 4B + 13 = 0–8a + 3b + 19 = 0multiply first by 3 and second by –4 and add9a + 12b + 39 = 032a – 12b – 76 = 041a – 37 = 0a = 37/416a + 8b + 26 = 06(37/41) + 8b + 26 = 08b = –26 – (222/41) = –1288/41b = –161/41check6a + 8b + 26 = 0–8a + 3b + 19 = 06(37/41) + 8(–161/41) + 26 = 0–8(37/41) + 3(–161/41) + 19 = 0222 – 1288 + 1066 = 0 ok–296 – 483 + 779 = 0 ok |
|