My dad has a Radeon HD 6650m on his laptop... I don't remember the exact benchmark score, but I do remember it looked playable. With an i5 and a graphics card that will likely outperform the one in my dad's laptop, I'm pretty sure you'll be able to run it relatively well.

If you can afford a Radeon HD 7770, I recommend it, as it plays ARR on my PC on ultra with an average of 40 fps. I have an i5 as well so you'd have similar results, I'd think.