#3. "RE: Nikon D3100 Can I use this card ?" In response to Reply # 0
Welcome to Nikonians! Congratulations on your new D3100. As JP wrote above, the Sandisk memory card will work in your D3100. I would recommend that you format the card in the camera before you capture your first image. Good Luck and Enjoy your Nikons!
#4. "RE: Nikon D3100 Can I use this card ?" In response to Reply # 0
The Extreme HD Video part of the name is just telling you that it is a very high-speed card. It can be written to fast enough to handle HD Video without a problem. So it will definitely handle your camera speed.
The Sandisk cards I have are the next step slower, and once in a while shooting fast in RAW mode, they will hold me up while writing to the card. The camera memory buffer is pretty good but you can fill it up with fast shooting & big files. The hold-up is never more than a few seconds, and I've never missed a shot because of it, but it is a little disconcerting.
The Sandisk web site has lots of good info about their cards.
And as others said, format it before use, and after each time you delete files. This helps prevent corrupted files.
working on it in Middle TN Nikon D3100 18-55 mm Nikkor VR 55-200 mm Nikkor VR 55-300 mm Nikkor VR 150-500 mm Sigma OS