Summarize your data and results in a concise, well-organized data table. Include sample calculations.

Centripetal Force Lab Purpose: (1) To study the nature of centripetal force. (2) To learn how to calculate the speed and acceleration of, and force acting on an object moving in nearly uniform circular motion. Apparatus: glass tube, string, rubber stopper, hooked masses, stop watch, paper clip, balance. Introduction: An object moving with changing speed in the same direction is undergoing acceleration. If an object moves with constant speed but in changing directions, it is also undergoing acceleration. Both types of acceleration require an unbalanced force. An object in uniform circular motion experiences an acceleration directed toward the center of its circular path. This is called centripetal acceleration, and the force producing it is called centripetal force. The equation that describes the centripetal acceleration is: a = v / r The equation that describes the centripetal force is : F= ma = mv/r. m = the mass of the object moving in the circular path v = the speed of the object moving in the circular path r = the radius of the circular path In this experiment, the centripetal force will be supplied by a mass tied to a string that passes through a vertical tube. See the figure below. The moving object will be a rubber stopper. The radius of the circle will be measured from the top of the tube to the center of mass of the rubber stopper. The speed of the stopper will be calculated using the equation: v= d / t = 2 n r/ t. Procedure: Pass the string attached to the rubber stopper through the glass tube. Attach a 100 g mass to the free end of the string. Practice whirling the rubber stopper overhead, in a circle of constant radius. You can use a paper clip attached to the string below the glass tube to check on the constancy of the radius. If the radius stays constant, the relative position of the paper clip to the bottom of the tube will also remain constant. Do not allow the paper clip to get "pinned" against the bottom of the tube. When you have learned how to keep the position of the paper clip constant, have your lab partners measure and record the time required for 10 complete revolutions. (Remember to start counting at zero, not at one). Use as many timers as possible to average out errors made in timing. When the timing is over, grab the string at the bottom of the tube before the speed of the stopper changes. Measure the distance from the top of the tube to the center of the rubber stopper. Record. Also record the weight of the hooked mass. Repeat the procedure for a total of three trials with the 100 gram mass.jibber, Atoppl Weight =) 19.89 Run three trials with a 200 g mass and three trials with a 300 g mass. Measure the mass of the rubber stopper. Remember that the rubber stopper is the object moving in the circle, so its mass is the "m" in the centripetal force equation. Calculate the speed, acceleration and centripetal force in each of the nine trials. Calculate the average centripetal force within each group of three trials and also calculate the percentage error three times. Summarize your data and results in a concise, well-organized data table. Include sample calculations. Prepare for a lab quiz on this activity. Radius Time 10 09 =) I trial - 76 Com 6:175, 5:21 bec - 63.5 (m 5 74 RX, 5.57 All TIT Ad - 53 am 5: 59 Rec, 5:42 Lle 200 g =) IN furial - 54.5 cm 4. 9 16ec ) 4.8 PACC - 99 cmm P.25 xec , 7:83 Hec - 28 cm 3. 35 Rec, 367 fee 3009 - I twal - 113um 6.47 dec. 6.72 kee - 62 umm 4. 98 Rec, 4. 73 /fee - 80 cm 5. 91/ec, 5 70 kee