Centripetal Force Lab
Data and Calculations Tables
Data Calculations
Trial / Hanging Mass(kg) / Mass of Stopper
(kg) / Total Time
(s) / Radius
(m) / Centripetal Force (Fc)
(N) / Period
(s) / Circumference
(m) / Speed
(m/s)
1 / 0.10
2 / 0.15
3 / 0.20
4 / 0.25
5 / 0.30
6 / 0.35
7
8
Example Calculations
Show the calculations for Trial 1 in the spaces provided below. Enter the results of the calculations in the appropriate spaces above.
1. Calculate the weight (Fc) of the hanging mass and enter in the table as the centripetal force.
2. Find the period of revolution by dividing the total time by the number of revolutions. Calculate the circumference of revolution from the radius.
3. Use the circumference and period to find the speed.
Analysis Questions
1. Using Logger Pro plot a fully labeled graph for Trials 1 -6 putting velocity squared (v2) on the x-axis and centripetal force (Fc) on the y-axis. Put the origin at (0,0) with an appropriate scale on each axis. Include a title, axis labels and units. Analyze your data using a linear fit and include the fit equation on your graph.
2. Use the slope of your graph to determine the mass of your stopper used in trials 1-6. Show the work for any calculations.
3. Determine the percentage difference between your calculated and measured value for the mass of the stopper used in trials 1-6. Account for any differences.
4. Using your results from trial 7 what effect did reducing the radius have on the speed of the stopper? Explain your answer! Hint: centripetal acceleration is related to the rate at which the stopper changes direction
5. Using your results from trial 8 what effect did changing the mass of the stopper have on its speed? Explain your answer! Hints: inertia and answer to 4
6. A student whirls a 40g stopper around their head on a string making a circle of radius 1.5m. What is the hanging mass attached to the string if 20 revolutions are timed in 19.7 s? Use the step method to determine your answer.
Name ______Date ______Hr ______
Scoring Sheet
1. Student has answered 3 primary questions ______(5 pts)
2. Student has filled out the data and calculation table correctly ______(5 pts)
3. Student has shown example calculations for Trial 1 ______(8 pts)
4. Student has plotted a fully labeled graph of Fc vs. v2
They have included a linear fit with equation ______(10 pts)
5. Student has showed how they have used the slope of the
graph to determine the mass of the stopper. They has included
work for required calculations ______(5 pts)
6. Student has calculated the percentage difference between the
calculated and measured values of the stopper’s mass and
accounted for any difference ______(4 pts)
7. Student has used their results from trial 7 to show what effect
reducing the radius has on the speed of the stopper. They have
explained their answer in terms of changing motion ______(4 pts)
8. Student has used their results from trial 8 to show what effect
changing the stopper’s mass has on the speed of the stopper.
They have explained their answer in terms of inertia and changing
motion ______(4 pts)
9. Student has shown used the step method to determine the hanging
mass attached to the string ______(6 pts)
Total ______(51 pts)