(c) M & S Marketing1 Sometimes it is difficult to accurately measure the acceleration of an object. However, it can be done using a ticker tape. A ticker tape is a narrow, long piece of paper that can be attached to an object while running through a ticker timer. The ticker-timer makes dots on the tape at regular time intervals – say 1/50 of a second. If we study the dots we can establish if the object is moving at constant velocity, constant + acceleration or constant – acceleration.

(c) M & S Marketing2 Motion of tapes Describe the kind of motion taking place in each tape. Explain how you can deduce this from the tape.

(c) M & S Marketing3 Calculating acceleration from ticker tape information.        A B C D 5 mm12 mm Direction of motion f = 50 Hz T = 1/f = 1/50 = 0.02 s Period: T = time between successive dots v AB = Inst. velocity midway in time AB

(c) M & S Marketing4        A B C D 5 mm12 mm v1v1 v2v2 v 1 = 0,005 / 0,02 = 0,25 m/s v 2 = 0,012 / 0,02 = 0,60 m/s a =  v /  t = 0,60 - 0,25 / 0,04 = 8,75 m/s 2 V 1 = ave V AB V 2 = ave V CD