Download Isaac Newton came up with 3 rules of behavior to describe all

Isaac Newton came up with 3 rules of behavior to
describe all motion. His second law can be written
as an equation: ΣF =ma
Objective:
Predict, write a procedure, collect data and analyze results to determine the
relationship between pulling force on a cart and its acceleration.
ΣF =ma
And just because it is cool:
https://www.youtube.com/watch?v=KFPvdNbftOY
Lab Equipment and Suggested Set-up:
Equipment:
• Mass set
• Pulley
• Pulley
holder
• Cart
• String
• Motion
sensor
• Labquest
• Old book
Another view. Note the book on the floor….
Pre-Lab questions. Answer on clean note paper.
1. T/F If no force is acting on a moving object it will eventually
stop.
2. T/F Weight and mass are two names for the same thing.
3. If I drop a 1 Kg brick and a 1 Kg pillow from the top of a
building, which one will hit the ground first if I let them go at
the same time and ignore air resistance?
4. Which has more mass? Which has more weight? Which has
more volume?
5. Using a real life example from your life; what is an example of
what happens to acceleration from a constant, unchanging
applied force?
6. Using a real life example from your life; what is an example of
what happens to acceleration from an increasing applied
force?
7. In the picture to the right, what is producing the force
which accelerates the system? (Where is this force
coming from?)
8. What object is this force acting on? Be very specific.
9. What objects is this force accelerating? (Hint: there
are 3 distinct set of objects with substantial mass)
10. What is the difference between mass and weight?
What is each measured in?
11. What will a “Velocity vs. Time” graph look like for the
motion represented by the cart?
12. What does the slope of a Velocity vs Time graph
reveal?
13. If the slope is linear what does that imply about the
acceleration? Recall how we highlighted the linear
portion of the VvsT graph in the Labquest to get the
slope/acceleration?
14. What is the difference between mass, force and
weight?
1. Write out the following responses on a new
piece of paper that you will be turning in:
2. Write a prediction (hypothesis/claim) of what
you think the relationship will be between
Σforce and acceleration. What life experiences
do you have to support your CLAIM? (Don’t
forget to talk about what needs to be done with
mass as force is varied on an object to see what
happens to acceleration.)
3. Write out a procedure of how you would go
about collecting data (EVIDENCE) to prove your
CLAIM.
4. Draw and label a data table (with ruler) that you
will fill in as you collect your data. (You need 5
different pulling force trials)
5. After collecting data, what data should we graph
in order to analyze the data? (Hint: what are we
trying to prove?)
Claim
Evidence
Reasoning
Questions for after you collect your data….
REASONING
• Answer these questions on your paper using complete sentences, and be
very descriptive. (Do not use “it” in your answer!)
1. What was the purpose for keeping the system’s mass constant in this
experiment?
2. Describe in your own words what the graph is revealing about the
relationship between force and acceleration.
3. What does the slope of your Force vs. Acceleration graph reveal? (Hint:
write out your rise axis units and divide them by your run axis units.)
4. Using your graph/data to support your answer, what did you discover as
the relationship between force, mass and acceleration? Be very
descriptive. Evidence!!!!
5. Calculate your % error using your slope as the “experimental value” and
the system’s mass as the “accepted, or theoretical, value.”