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## Homework Statement

A bolt is dropped from a bridge under construction, falling 98 m to the valley below the bridge.

(a) In how much time does it pass through the last 30% of its fall?

(b) What is its speed when it begins that last 30% of its fall?

(c) What is its speed when it reaches the valley beneath the bridge?

## Homework Equations

## The Attempt at a Solution

Tried splitting the problem into 2 parts by multiplying 98 x .3 to solve for the final velocity for the first 70% of the fall, then using that velocity as the initial velocity for the 30% of the fall and the other 30%(29.4m) of the trip.

[tex]\Delta[/tex]t=-vi +/- [tex]\sqrt{vi^{2}+2ay}[/tex] / a