If you completed all class assignments and made a perfect score on the final, then that is an example of how you applied yourself.
A certain rule than needs to be followed only by certain people is an example of rules that are applied to certain people.
If you pressed on the brakes to stop the car, then that is an example of how you applied the brakes.
Using science to figure out the volume of water in a swimming pool is an example of an applied science.
If you answered questions about yourself and your work experience in hopes of getting a job, that is an example of applied for a job.