Transcript Modified Atwood Lab Guidelines

Modified Atwood Lab
Discovering Newton’s 3rd Law
Materials & Equipment
You will be using both force probes and motion
detectors in this experiment.
The other materials include on cart, metal ramp,
pulley, string and mass set.
Be sure that you are careful with your data
acquisition as this will certainly affect your overall
results.
Experimental Set-up
Motion Detector
Cart with Force Probe
Pulley & String
Mass Hanger
Foam Pad
Part 1: Obtain an A vs. F graph
After constructing the experimental set-up, you will
use Logger Pro to obtain a Velocity Vs. Time as well
as a Force vs. Time graph for 8 different masses.
In this part of the lab, you will change only the
MASS ON THE HANGER in increments between 20
and 50 g.
Remember: The hanger already is 50 g
From the Velocity Vs. Time graph, you will
determine the acceleration for each mass.
You will determine the Force by averaging
two points on the Force vs. Time graph for
each mass.
Create a data table for each mass that
corresponds to your acceleration and your
force. Ultimately, you will use this
information to create your A vs. F graph.
Pitfalls
1. Calibrate the Force probe before starting
the experiment.
2. Stop the cart before it touches the foam
pad.
3. Be careful with determining which parts
of the graph to use for the force and
velocity graphs.
Part 2: Obtain an A vs. M graph
You will use Logger Pro to obtain a Velocity Vs.
Time graph for 8 different masses.
In this part of the lab, you will change only the
MASS ON THE BACK OF THE CART in increments
of 100 g.
The cart & force probe are 580 g to start!!!
From the Velocity Vs. Time graph, you will
determine the acceleration for each mass.
Create a data table for each mass that
corresponds to your acceleration.
Ultimately, you will use this information to
create your A vs. M graph.
Pitfalls
1. Calibrate the Force probe before starting
the experiment.
2. Stop the cart before it touches the foam
pad.
3. Be careful with determining which parts
of the graph to use for the velocity
graphs.