Figure 3. Details of an air track When Newton's Second Law is applied to the two bodies, the acceleration of the system is a =- (3) Apparatus o air track with air supply and sparker o glider o spark tape o meter stick o masking tape o hanging masses o masses to be attached to glider The air tracks have been leveled. Procedure to get data (Just for your information) 1) Use masking tape to attach a one-meter length of spark tape to the pulley end of the yellow-colored mounting strip on the air track. 2) Attach the amount of mass corresponding to your group number to the glider. (Refer to Figure 2.) Be sure to equally distribute the total mass to both sides of the glider. Record the mass of the glider and the total mass added to the glider. This mass is on. 3) Carefully place the glider on the air track. Pass the string over the pulley and attach to the end of the string the amount of mass listed for your group number. 4) Turn on the air supply. (The air flow is adjusted high enough so that the glider floats above the surface of the track.) Set the spark timer to the proper frequency. Prevent the glider from moving by placing your finger on the air track in front of the glider. 2 5) Start the spark timer, then release the glider. Keep the spark timer engaged until the glider reaches the end of the air track. 6) Carefully remove the spark tape and affix it on a flat surface with making tape. Cross out the dot corresponding to the starting position. Circle the remaining dots and number the dots successively. Place the meter stick on the tape and record the position of each dot. A suggested form for the table for each set of data is shown in Figure 4. time, date multiples distance, Distance, change in Average velocity Acceleration point of At AS S= sil-1+Asi distance, As (Si+1-5i-1 )/2At 2 1.00 53 - 51 (53- 5, )/ 2At 2.00 $4 - 52 ($4 - 5))/ 2At 4 3.00 $5 - 53 ( $s - 53)/ 2At (etc Figure 4. A suggested form for the data table. For definitions see below)5) Start the spark timer, then release the glider. Keep the spark timer engaged until the glider reaches the end of the air track. 6) Carefully remove the spark tape and affix it on a flat surface with making tape. Cross out the dot corresponding to the starting position. Circle the remaining dots and number the dots successively. Place the meter stick on the tape and record the position of each dot. A suggested form for the table for each set of data is shown in Figure 4. time, data multiples distance, Distance, change in Average velocity | Acceleration point of At As S= all-1+Asi distance, As (51+1-5-1)/2At 0 2 1.00 53 - 51 (53- 5, )/ 2At 1 2.00 ES 54 - 52 ($4 -5))/ 2At 4 3.00 54 $5 - 53 ($5 - 53)/ 2At (etc Figure 4. A suggested form for the data table. For definitions see below) PL.6 As Typical 2 10 1 12 13 14 15 16 17 18 19 20 21 22 23 24 25 HON 3Data: Use following data for your analysis: my = 14 my = 150 + 214-6 time interval = 1/65 Analysis Draw free-body diagrams for the two masses, my and mz. Apply Newton's Second Law and derive (3). M2 MI w= mp N W = 137. 341 Complete the calculations of the average velocities for the data. First calculate the distance from one data point to the second data point away, As. Then find the average velocity by dividing As by the time taken to travel that distance, 2At, which is twice the park timing interval. Because the acceleration is constant, the average velocity is numerically equal to the instantaneous velocity at the point halfway in time between the data points. Change in Average Data Time, Time distance As velocity Acceleration Point multiple (sec) As (cm) Distance, s (cm) (cm/s) n (cm/s-) of At From (cm) (Si+1 - Si-1) (si+1 - Si-1 )/2At a = Vave/t above S = Sj-ItAsi fig L 0 O O 167 0.85 0'89 2. 10 6.29 32.65 10.33 3 1.25 2. 10 2.86 6. 5.C 25. 74 + 61 5. 70 3. 86 1. 3 123 . 16 10. 6 67 2.25 5- 24 23 . 58 10 623 2. 99 6-90 10 . 70 2.9 4-50 25. 50 1. 67 4.59 17. $5 28 . 32 124- 279 8 1 : 3 33 4. 85 22. 30 10.05 30.15 22.61 10 9 100 5.20 27-50 Note: At = 1/6 s Graph the values of instantaneous velocity versus time, with velocity as the ordinate and time as the abscissa. Draw two lines that best fit the data: one with maximum slope, amex, and one with minimum slope, amin- Emax = Amin= a = (amax + amin)/2 Acceleration, Max. a Min. a Ave. From above table t, sec Vave, Amax - t Amin.t a.t v (cm/s)) t (s 5Find the slopes of these lines. The best value for the acceleration of the system is then a= (amex + amie ), * (4) and the corresponding uncertainty in the acceleration is Aa = -(dmax - amin ). (5) Calculate the best value for the acceleration, (4) and the uncertainty, (5). 0 = Aa = On a one-dimensional graph, use points and error bars to plot a + Aa. Be sure to displace vertically the error bar from the axis so that it is clearly visible. Now calculate the theoretical value of the acceleration from (3) and plot it on the graph described above so that the point is displaced slightly above the error bar. One-dimensional graph Conclusions Indicate what the major sources of error are and explain how the experimental values are affected by these sources of error. Explain whether or not the experimental value of the acceleration shows the effects of the sources of error. Answer: 6Questions 1) If friction is present between the glider and the air track, then how will the experimental value of the acceleration be different from the theoretical value? Explain why. Do the results indicate the presence of friction? Explain by using Free Body Diagram. 2) If the mass of the pulley is not negligible, then how will the experimental value of the acceleration be different from the theoretical value? Explain why. 3) If the experimental value of the acceleration is greater than the theoretical value, then what is the most likely reason for this