The distance that a free falling object falls is directly proportional to the square of the time it falls (before it hits the ground). if an object fell 64 ft in 8 seconds, how far will it have fallen by the end of 9 seconds

If the distance is proportional to the square of the time, then the distance in 9 seconds will be  (9/8)²  as long as the distance in 8 seconds.

(9/8)² = 1.265625

(64 ft) · (1.265625) = 81 ft.

unable to answer the rest since your question is incomplete

hi there!

out of the two, (b) precision would be more reasonable.   however, both a and b could be pretty reasonable.

-awesomerepublic   : )