Looking for a Light, Powerful Laptop

I'm about to come into some money in the form of a scholarship that gives me a fair amount (~$700 U.S.) towards the laptop of my choosing. I'm willing to up to around $1000 if needed, though. I'm a high school senior about to graduate and begin preparations for a college career studying electrical engineering. I honestly don't know if I will be using any kind of intensive software, but I do know that the school i'm going to has computer labs available for use practically 24/7.

The main things i'm looking for in a laptop are:

  • Light (<5 lb.)
  • Powerful (I may need a decent amount of power, it depends on whether the school provides software or not.)
  • Preferably 13'-15'in screen(1600x900 or 1920x1080), whichever will be best with the other needs.
  • This isn't necessary, but i'd love it if it was easily serviceable in case something breaks.
I don't have any other constraints after those, your input would be greatly appreciated!