# Weight In An Elevator

1. Apr 10, 2005

### yeshli2nuts

I had to do this problem for school but I couldn't figure out how to do it so I need some help. Lets say I weigh 165 pounds and im standing on a scale in an elevator that accelerates to 1 meter per second and then stays at the constant speed of 1 mps. How would my weight change during the acceleration and then balance out when the elevator stops accelerating? Any help would be great. Thanks

2. Apr 10, 2005

### Pengwuino

Which way is the elevator accelerating?

3. Apr 10, 2005

### Jameson

Draw a force diagram... and remember that $$F_{net} = ma$$

4. Apr 10, 2005

### yeshli2nuts

can I get both?

How do i get the mass with only knowing 165 pounds? (sorry, I'm pretty bad at physics...which is why I'm here)

5. Apr 10, 2005

### Pengwuino

Gravity has a constant acceleration. When you are "165 pounds", what is actually being measured in the force you are exerting on the ground which is 165pounds/s^2 = mass * acceleration. Acceleration on earth is a constant 9.8m/second. So you divide 165 by 9.8 to get your mass. Then multiply it by 10.8 if hte elevator is accelerating upwards or 8.8 if the elevator is accelerating downward to get your approprate weight during those accelerations (+1 and -1). At constant speed, acceleration due to the elevator is 0 so your still 165 pounds because the overall acceleration is still 9.8m/s.

6. Apr 10, 2005

### Werg22

Ask yourself which way does gravity accelerates? In what direction does the elevator accelerates...? Simple arithmetics.

Last edited: Apr 10, 2005
7. Apr 10, 2005

### yeshli2nuts

thanks a lot guys, thats exactly what i needed.