Elevator Motion Lab 
by Mary Norris, Virginia Tech mnorris@vt.edu

Purpose 
To investigate forces, Newton's 2nd and 3rd laws, and free body diagrams

Procedure 

Draw a freebody diagram for a person standing on a scale in the elevator: a) at rest; b) accelerating upward; c) accelerating downward; d) moving at a constant velocity upward or downward.

Fill in the first two columns (your hypothesis).

Write the scale readings in pounds in the table when we ride the elevator. Convert these to Newtons (1 lb=4.45 N).

Record the persons’s weight on your freebody diagram.

Compute the net force for each part of the elevator ride.

Compute the person’s mass. Remember that weight in Newtons is mass in kg times 9.8!

Find the person’s acceleration. (Use F=ma.)

Write a few sentences that answer the following: If you wake up in an elevator and there are no windows or lights, can you tell if you are moving or not? How?

Data 
Data table 

Elevator Motion 
Hypothesis
Direction of F_{net}_{} and a_{net}
(up, down, zero) 
Scale Reading(N)
(This is the normal force!)
Scale Reading
(more, less, weight) 
F_{net}_{}
(N) 
a_{net}
m/s^{2} 

1. At Rest 




Going Down 
2. Speeding up at top 




Going Down 
3. Constant speed downward 




Going Down 
4. Slowing down at bottom 




Going Up 
5. Speed up at bottom 




Going Up 
6. Constant speed upward 




Going Up 
7. Slow down at top 





8. Cable Breaks 





