Motivational (adjective)

1. Designed to inspire or encourage someone to do something.
2. Providing or giving a reason for doing something.

Origin:

Late 19th century: from motivation + -al.

Examples:

1. The speech was motivational and inspired the audience to take action.
2. The book was a motivational guide to achieving success.
3. The coach was motivational and helped the team to win the game.
4. The poster was motivational and had a powerful message.
5. The video was a motivational tool for the sales team.