Title: Riding the Elevator with Isaac
Obj: Determine the
acceleration of an elevator using ΔForce
Materials: Elevator, force sensor with Pasco Xplorer7,
ring stand with bar, 1 kg mass, DataStudio7 on computer, bathroom scale
1. Sketch the free body diagrams
(FBD) of the elevator initially accelerating down, at constant down velocity,
stopping at the bottom, accelerating up, stopping at the top (total of 5 FBD).
2. Take the Xplorer7
apparatus to the elevator, placing the stand on the floor of the elevator. Have one or two students also stand on a
bathroom scale and observe changes in weight.
3. Turn on Xplorer7, then press the zero button on the force
sensor to set the 1 kg mass to a value of zero Newtons. (You may not get exactly zero even after
several tries, so simply continue with the next step.)
4. When ready, push the elevator G
button to go down, then immediately as the door is closing press the large
button on the Xplorer7 to start recording force.
5. When the elevator stops on the
G floor, press the button again to stop recording. This is the data set
called Run One.
6. Repeat Steps 3-5, except push the
elevator 2 button for the upward return trip. This is Run Two.
1. Retrieve your two data sets
from Xplorer7 onto the computer as described by the physics teacher.
2. Find the Data icon, then
select Run One, then Run Two, each time printing the graph (hit
3. For Run One, find the maximum
negative force. This is the weight lost
by the 1 Kg mass while accelerating downward.
Determine the acceleration of the elevator using Newton’s 2nd
4. Repeat Step 3 for the stop at
the Ground Floor. There may be two force maximums; choose the 1st
5. Repeat acceleration calculations
for the up ride.
6. Where did you feel lighter? Heavier?
Explain in terms of the elevator’s normal force.
7. Is the ride on the elevator a smooth
one? What evidence on you graph
8. Describe how Newton’s 1st
and 3rd laws relate to an elevator ride? Be specific because this is your summary.
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