Vector: How do you figure this out?

Question

R = A x B

and

R = (A x B) *C

(*) is a dot product rule

(x) is cross product rule

A = 30.0m, 30 degrees

B = 40.0m, 125 degrees

C = 35.0m, 300 degrees

I tried doing the right-hand rule but I still dont understand...please help!

Answer 1

If vectors are on XY plane, then R = 0

Here is how.

A and B are in XY plane. Therefore, A X B is parallel to z axis.

C is in XY plane.

z axis is perpendicular to XY plane.

You are taking dot product of A X B and C. This means you are taking dot product of two perpendicular vectors.

The dot product of two perpendicular vectors is zero.

So R is a zero vector, also called null vector.