What is one example of a past participle and one example of a present participle?

the boy's acceleration toward the girl is 2.08 m/s^2.

explanation:

according the newton's third law, the force causing the girl accelerate towards the boy will be me with equal counter-force causing the boy to accelerate towards the girl. these forces will be of equal magnitude and allows us to determine the boy's acceleration:

the boy's acceleration toward the girl is 2.08 m/s^2.

i think the correct answer would be adjustments in life roles.  this causes for one to adjust or change totally his/her career or lifestyle since the present is not beneficial to the life role he is at. for instance, you became a mother you would of course stop going to malls and enjoying life outside. you would be staying at home taking care of your child.