I'm sorry i couldn't write the problem out so i just scanned the photo instead. We did this problem in our phase test at school and i got it wrong and since i did and not given the papers back i would like to understand the problem with your help.

Photobucket link
HTML Code:
http://i37.photobucket.com/albums/e65/TrippedCameron/Physics-1.jpg

Many thanks

Cameron