The expression 16^2 models the distance in feet that an object falls during t seconds after being dropped. what distance will an object fall in 3 seconds?

Just "plug in the values":

o. 25 seconds:

16t^2 = 16 (0.25) ^2 = 16 (0.0625) = 1 feet

.

0.5 seconds:

16t^2 = 16 (0.5) ^2 = 16 (0.25) = 4 feet

.

2 seconds:

16t^2 = 16 (2) ^2 = 16 (4) = 64 feet

.

10 seconds:

16t^2 = 16 (10) ^2 = 16 (100) = 1600 feet