# Homework Help: Simple Vectors

1. Oct 1, 2005

### pattiecake

This is actually homework for calc. III, but...eh...

The nine Ring Wraiths want to fly from Barad-Dur to Rivendell. Rivendell is directly north of Barad-Dur. The Dark Tower reports that the wind is coming from the west at 68 miles per hour. In order to travel in a straight line, the Ring Wraiths decide to head northwest. At what speed should they fly (omit units)?

Does anyone know how to attempt this problem when they don't give either the distance from Barad-Dur to Rivendell or the angle they are heading northwest?

2. Oct 1, 2005

### pervect

Staff Emeritus
The way I interpret the problem, they do give you the angle. When they say that the Wraiths are headed northwest, I think they mean that the airspeed of the Wraiths is directly northwest, i.e. at an azimuth of 315 degrees (0 degrees being north, 270 being west).

3. Oct 7, 2005

### khiamabbasi

the cross product of the two vector quantity is called phseduo vector can the product of two phseduo vector is phsedo vector if yes give example if no why?

4. Oct 7, 2005

### arildno2

Barad-dur is more easterly of Rivendell than northerly..:grumpy:

5. Oct 7, 2005

### Tom Mattson

Staff Emeritus
Then it should be in the Homework Forum.