A bolt is dropped from a bridge under construction, falling 83 m to the valley below the bridge. (a) How much time does it take to pass through the last 20 % of its fall? What is its speed (b) when it begins that last 20 % of its fall and (c) just before it reaches the ground?
The Attempt at a Solution
For part (a) I got the correct answer of .436 seconds by doing 83/4.9=16.94, sqrt16.94=4.12
83 x .20 = 16.6
That answer was correct but I need parts (b) and (c)