Yes, and because it is a Class-10 card it will store photos and video faster than most other cards, it would be an excellent choice for this camera. This is confirmed by the manufacturer's manual, available at this link:
I am not sure. I use it on a Sony CX-160 video camera at 1920x1080p @60fps max resolution and it takes it like it like a champ. My still camera is a Canon 10MP and it's video and stills works just fine. Don't know about the SX40 however. It should work. I use it for video of action shots and nature shots. Never gave any troubles yet.