# Homework Help: Gravitational Potential Energy of an elevator

1. Oct 25, 2007

### BuBbLeS01

[SOLVED] Gravitational Potential Energy

1. The problem statement, all variables and given/known data
Calculate the change in potential energy of a 77.2-kg man when he takes an elevator from the first floor to 24th floor, if the distance between floors is 4.05 m.

2. Relevant equations
Ug = mgy

3. The attempt at a solution
Ug = (77.2kg)*(9.81m/s^2)*(24*4.05m) = 73612.67N*m

What am I doing wrong??

2. Oct 25, 2007

### Kurdt

Staff Emeritus
If the man travels from the first floor to the second floor how high is he?

3. Oct 25, 2007

### BuBbLeS01

4.05m

4. Oct 25, 2007

### BuBbLeS01

oh nevermind...

5. Oct 25, 2007

### Math Jeans

Your equation seems to be correct. I don't see any immediate problem. Just make sure you did not misread or mistype it.

6. Oct 25, 2007

### Kurdt

Staff Emeritus
Did you get it or just didn't like my hint?

7. Oct 25, 2007

### BuBbLeS01

LoL...I'm sorry...I got it...I was supposed to do 23*4.05m