# Elevator going down and you drop a book

1. Oct 5, 2008

### kmiller

1. The problem statement, all variables and given/known data

While riding on an elevator descending with a constant speed of 3.3 m/s, you accidentally drop a book from under your arm.
(a) How long does it take for the book to reach the elevator floor, 1.1 m below your arm?
s
(b) What is the book's speed (relative to the earth) when it hits the elevator floor?

3. The attempt at a solution

4.9m/9.8m/s2=14.7
squareroot 14.7=3.834=answer a

1.1m+1/2(13.1)t
t=7.65
1.1m/7.65s=.1437=answer b

both of these answers were wrong. what equations am ia supposed to use?
how do i start?

2. Oct 6, 2008

### Kurdt

Staff Emeritus
For the first part it looks as though you're trying to use the correct equation but I have no idea where you got your numbers from?

For part b it will just be the speed of the elevator added to the speed you work out from standard kinematic equations.

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook