# Homework Help: X and Y Components

1. Nov 15, 2012

### vriti1D

1. The problem statement, all variables and given/known data
A 525 kg boat is sailing at 4.5 m/s, east. One minute later it is sailing at 3.5m/s, 45 degrees. During this time, 3 forces act on it. Two of the forces are 25 N,78 degrees, and 32 N, 21 degrees. a) find the horizontal and vertical components of the initial and final velocity. b) find the horizontal and vertical components of the average acceleration. c) find the horizontal and vertical components of the sum of the forces. d) find the horizontal and vertical components of the missing force.

2. Relevant equations

3. The attempt at a solution
a) I got vxi=4.5m/s vyi=0m/s vxf=2.47m/s vyf=2.47m/s
b)I have no idea how to find the average acceleration using any of this

Last edited by a moderator: Nov 17, 2012
2. Nov 15, 2012

### Simon Bridge

Huh! Well, on calm seas, the vertical components are both zero!
But you are probably correct to think the question means NS and EW components.

You should make sure by specifying where your x and y axis points in terms of the compass.

OK - so we can make +y as N, and +x as E ... but is the 45degree bearing to the east or west of north?

Anyway - you seem to have been able to do (a)

For (b) ... average acceleration is given by: $$\vec{a}_{ave}=\frac{\Delta\vec{v}}{\Delta t}$$