Which is not a sentence fragment?
a. she went to bed.
b. the snow on the railing.
c. trying to fix the car.
d. forget my jacket all the time.

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.