# Velocity & Acceleration of Elevator

1. May 4, 2011

### mimo6267

When the elevator approaches the top of a building and slows to a stop, what direction is the elevator's velocity & acceleration?

2. May 4, 2011

### praharmitra

kindly explain what you believe is the answer and why? or what you have done so far. You cannot expect us to answer your questions directly.

3. May 4, 2011

### mimo6267

I found that since the elevator is slowing to the stop, the direction of the elevator's acceleration would be downward. Since the elevator is always traveling at a constant velocity, does that mean when it slows to a stop, the velocity would still be constant, which means the direction would be horizontal? or since, the acceleration is downward that direction of velocity would also be downward? Thank you!

4. May 4, 2011

### olivermsun

At the moment that the elevator is stopped, it doesn't really have a "direction." (E.g., Which way does an arrow with no length point?)

At any other moment the velocity certainly has a direction (which you seem able to describe)!

5. May 4, 2011

### praharmitra

You're absolutely right about the acceleration. However, the elevator is NOT travelling at constant velocity!

For an object with constant velocity, its acceleration must be zero, which is clearly not the case here. Now at its top most point the elevator slows down and comes to a complete HALT before moving downwards again. At that point therefore, the velocity of the elevator is ZERO!

Also, the zero vector doesn't really have a defined direction.