# Physics questions from homework

1. Sep 30, 2006

### Aleksandar

Can someone help me with the following questions for homework?

1. Consider the vector A=7i + 3j - 6k. Find the most general vector in the yz-plane that is perpendicular to A.
2. Show that the magnitude of the vector product of two vectors is the area of the parallelogram for which the two vectors form adjacent sides.

Help me, I'm desperate. They might be easy, but I've tried and its no use. If you can solve this problems somehow with full solutions. PLEASE

You can also e-mail me on:
ikkakumon100@yahoo.com

2. Sep 30, 2006

Hint regarding 1: What does the scalar product of two perpendicular vectors equal?

3. Sep 30, 2006

### Aleksandar

Scalar product of two perpendicular vectors equals zero, right?, since cos(alpha) of 90 degrees is zero, therefore it should equal to zero.

4. Sep 30, 2006

### Aleksandar

I guess I have forgotten many things about vectors, including their properties. So if the dot product of two perpendicular vectors would equal zero, how can that help figure out the most general vector in the yz-plane that is perpendicular to that vector A, in the previous post given.