Automatic
な adjective
An automatical (自動 + 的) thing of course isn't "automatical." A better way to say it is to cut off the -al and call it automatic.
じどうてき
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well. It will help to know the reading of 自動 as well.
この電車のドアは、自動的には開きません。
This train's doors don't open automatically.
あの国が戦争を始めると、俺たちの国も自動的に戦うことになるんだよ。
If that country starts a war, our country will automatically be drawn into the conflict as well.
こちらに自動的にバックアップされたデータは、今度は一定期間後に自動的に消去されるシステムになっています。
The data automatically backed up here is managed by a system that will also automatically delete it after a certain period of time.
これは、30分以上何もしなかった場合の自動的なログアウトによるものですね。
This is due to an automatic logout after more than 30 minutes of inactivity.