# Hw help with vector natur of newton's second law of motion

1. Sep 27, 2006

### ersc13

only two forces act on an object (mass = 3.00 kg). 40.0N east and 60.0N north of east at 45 degrees. Find the magnitude and the direction (relative to the x axis) of the acceleration of the object.

I don't really know where to begin.

2. Sep 27, 2006

### Staff: Mentor

Add the components of the two vectors to make a sum vector. Add the two components in the N direction to get the N sum, and add the two components in the E direction to get the E sum. How do you break up the 2nd vector into its N and E components? All you need is a little trig.

3. Sep 27, 2006

Use the relationships: $$F_{x} = F\cos\theta, F_{y} = F\sin\theta$$