Question

Physics:

In the figure below are three vectors. Vector A has a length of 39.0, B's length is 63.0, and C is 21.0. Find the following magnitudes and directions: At what angles above and below the horizontal line could vector A be at so that A Times B = 0? 90 degree above, or 70 degree below 110 degree above, or 70 degree below 0 degree above, or 180 degree below 20 degree above, or 160 degree below

Answer 1

The cross product of the vectors A and B is, (39)(63)sin(70-20°) 1882.17 The cross product of the vectors C and B is, (21) (63)sin (70°+20) -1323 In both the cases the value of θ is the total angle between the vectors A and B. in the first case and C and B in the second case. For the direction, curl your fingers from A to B and the thumb goes into the page and therefore negative z direction in the first case In the second case, similarly when you curl fingers from C to B, the thumb goes out of the page and hence positive direction. Consider AxB 0 B|sin(θ 20°)-0 20°-0° or 180° 8 20° or 160° θ Therefore the vector A should be either at 20° above or 160° below