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## Homework Statement

A runner accelerates from 0 to 15 ft/sec in 2 seconds.

She goes at a constant v from 2 sec to 10 sec.

She deccelerates to 0 at the 20 sec mark

Q: How much distance does she cover?

## Homework Equations

## The Attempt at a Solution

Here is my work:

From 0 to 2 sec, she accelerates from 0 ft/sec to 15 ft/sec.

Her average velocity is 7.5 ft/sec, so in 2 sec she covers 7.5 ft. (round to 8)

From 2 sec to 10 sec, she goes at a constant velocity of 15 ft/sec, so the distance covered is 15ft/sec*8sec, which is 120 feet

From 10 sec to 20 sec, she decelerates from 15 ft/sec to 0 ft/sec

Avg velocity of 15ft/sec / 10 sec = 1.5 ft/sec * 10 sec = 15 ft

8 ft + 120ft + 15ft = 143 ft in 20 sec.