Thread: how can get anything from this?....

Three forces AB and C act at, and away from, the orgin of a three-dimensional coordinate system. Force acts along the x axis and has a magnitude of 3 N; force B acts along the y axis and has a magnitude of 5 N; force C acts along the z axis and has a magnitude of 2 N. Evaluate the magnitude of the resultant force and specify the angle to the xy plane at which it acts. The resultant force and its projection both lie in a plane at an angle X to the xz plane. Find this angle between these two planes.

thanx

x

Originally Posted by steph21

Three forces AB and C act at, and away from, the orgin of a three-dimensional coordinate system. Force acts along the x axis and has a magnitude of 3 N; force B acts along the y axis and has a magnitude of 5 N; force C acts along the z axis and has a magnitude of 2 N. Evaluate the magnitude of the resultant force and specify the angle to the xy plane at which it acts. The resultant force and its projection both lie in a plane at an angle X to the xz plane. Find this angle between these two planes.

thanx

x

Hello steph21,

Lets write each of your vectors in component notation.


Now our resultant force is the sum of all the forces.



The magnitude of the force is the vector's length



To find the angle between the vector and the xy plane lets draw a right triangle. Lets start by drawing a line from the origin to the tip of the vector, and from the tip of the vector drop a perpendicular into the xy plane.

We know both of these distances. The length of the vector is its magnitude and the perpendicular is the z component of the vector. We can find the angle by using the

For the last part try to find a different triangle. Good luck.