Circular Motion Investigation In this IB Lab you will be assessed on the following IB criteria :- Data Collection, Data Processing and Evaluation Aim: To investigate circular motion and to use the formula for centripetal acceleration to calculate the mass of a rotating object. Diagram: Reaction force (mv2) Centripetal force ( mx2) FR = Reaction Force m = mass of ball V = speed r = radius of rotation T = time for 1 rotation FR Path travelled by ball Apparatus: Grass tube, rubber cork, string, meter rule, stopclock, masses and mass holder. Theory: When the system is in equilibrium FR = Fc (speed and radius of rotation remain constant) Method: 1. Set the force, FR, hanging from the string and record it. 2. " Rotate the string and record the radius, r, and time period, T. 3. Change the force, FR and repeat until 6 to 8 sets of data are recorded. Data Collection: In a suitable table record all of the data collected. · Include actual and percentage uncertainties due to the measuring apparatus used. Data Processing and Presentation: · Draw a suitable graph that will allow you to use the formula for centripetal acceleration in order to calculate the mass of the rotating object. Conclusion and Evaluation: · Evaluate the results of the experiment - compare your results by taking the mass of the object using a balance. · Evaluate the procedure, including any modifications you had to make to overcome problems. Include an evaluation of the apparatus used. · Suggest ways in which the procedure could be modified in order to improve it for the future. Mike Dickinson