Circular Motion Lab (Gizmo)


Purpose: Determine relationship between tangential velocity and Force (centripetal) and the relationship between radius and force (centripetal).

Experiments:

1)Hold radius and stopper mass constant - change number of washers.
Graph FORCE vs. VELOCITY.

2) Hold # of washers and stopper mass constant - change radius.
Graph RADIUS vs. VELOCITY.

3) AP only - Hold # of washers and radius constant - change mass of stopper.
Graph MASS vs. VELOCITY



Data:

1) Constant Radius (m):
Mass of stopper (kg):
Average mass of one washer:
Number of washers (kg)
Time for 10 rotations

10+ trials
2) Constant # washers:
Mass of Stopper:
Average mass of one washer
Radius (meters)
Time for 10 rotations

10+ trials

Computer Spreadsheet:


1) . Graph of Force vs. Velocity
Number of Washers
Radius (m)
Time for 10 Rev (sec)
Period (T) = Time/10 (sec)
Velocity= 2*Pi*r/T (m/s)
Mass of Washers (# washers *mass of one washer) (kg)
Force of washers
(F = mg) (N)








1) Graph of Radius vs. Velocity
Trial
Radius (m)
Time for 10 Revs (sec)
Period (T)= Time/ 10 (sec)
Velocity= 2*Pi*r/T (m/s)
10+ trials





Graph:
Google Drive: Data & Calculation Table and Graphs

Graphs:
Radius vs. Velocity & Radius vs. Velocity^2
Force vs. Velocity & Force vs. Velocity^2


Calculations:
1. Draw two force diagram - the stopper and the washers
2. Sample calculations for:
Average Period
Velocity
Average Mass of washers
Force of washers

3. Rewrite formula for graphs after you have a straight line. Don't forget units.


Questions:
1. What are the variables that were held constant for each experiment?
2. What is the independent and dependent variables for each experiment?

CONCLUSION
Purpose, results (include formulas of graphs), discussion (what do the slope, y-intercept and area under the curve mean - if anything) , 3 detailed errors. how to improve if had a chance to re-do.

Rubric for Conclusion


Purpose
2

Results -include relationship of 1st graph and formulas of 2nd graph from each set.
5

Discussion (what do the slope, y-intercept and area under the curve mean?
8

Errors
3

Improvement
2









Extra Data - Use this data if yours is completely awful

Directions:Use the following data to make Excel data tables and Graph.
Cut and paste data table and graph onto document with relationships and formulas (see below)
Submit on Google Docs.

1.
Force (N)
Velocity (m/s)


0.15
1.22 
0.3
1.73
0.45
2.12
0.6
2.45
0.75
2.74
0.9
3.00 
1.05
3.24
1.2
3.46
1.35
3.67


a. Graph Force vs. Velocity
b. State the relationship, include best-fit curved line.
c. Graph Force vs. V^2
d. State the relationship, include best-fit straight line and re-write the formula to include units and symbols.

2.
Mass (kg)
velocity (m/s) 


0.1
2.00 
0.2
1.41 
0.35
1.07 
0.5
0.89 
0.75
0.73 

a. Graph Mass vs. Velocity^2
b. State the relationship, include best-fit curved line
c. Graph 1/mass vs. V^2
d. State the relationship and write the formula, include best-fit straight line

3.
Radius (m)
velocity (m/s) 
0.1
1.58 
0.15
1.94 
0.2
2.24 
0.3
2.74 
0.4
3.16 
0.5
3.54 
0.6
3.87 

a. Graph Radius vs. Velocity
b. State the relationship, include best-fit curved line
c. Graph Radium vs. V^2
d. State the relationship and write the formula, include best-fit straight line