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zap123 
Posted: Aug 27 2005, 05:22 AM

Newbie Group: Members Posts: 3 Joined: 27August 05 Positive Feedback: 0% Feedback Score: 0 
Im doing a project on how to learn how to use a ticker timer and
investigate acceleration using a ticker time . Equipment: Car String Weights Clamp x2 Ticker Timer Strand of paper Heres my results Distance Seconds Distance from 0 5.3 0.1 dot 1 5.3cm another 6.2 0.2 dot 2 11.5cm another 10.1 0.3 dot 3 21.6 cm another 12.5 0.4 dot 4 34.1 cm another 15.1 0.5 dot 5 49.2cm My question is Did the trolley stop accelerating at any time? Justify your answer Calculate the average acceleration? (How u do that?) Describe what each graph is telling you. Point out that parts on graph that represent acceleration and constant speed? CAN SOMEONE ANSWER MY QUESTIONS??? PLEASE??? 
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zap123 
Posted: Aug 27 2005, 05:39 AM

Newbie Group: Members Posts: 3 Joined: 27August 05 Positive Feedback: 0% Feedback Score: 0 
CAN ANYONE HELP ME????

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Strider 
Posted: Aug 28 2005, 09:10 PM

Newbie Group: Members Posts: 8 Joined: 10August 05 Positive Feedback: 0% Feedback Score: 0 
To make it easier to see, I first graphed it in excel.
1. The trolly would stop accelerating if the velocity would stop changing, or on the graph, the line would become straight at a 45 degree angle to the base. I can't really tell without more measurements, but it looks like towards the end, it does seem like it stopped accelerating. 2. First of all you need to find the change in velocity before you can find the acceleration. I assume you don't have to come up with an equation to fit your data points, so I don't think you'll need the differential equations, but I'll throw them in anyways. They are useful if you need to find the exact velocity or acceleration at a certain time, not just an average like what I'll be doing below. Velocity = change in distance / change in time or v=d/dt(distance) where t=time in sec (d/dt means take the derivative of equation with respect to variable 't' which is time in our case) Acceleration = change in velocity / change in time or a=d/dt(velocity) To find the velocity of each time interval we'll use this equation instead of using derivatives because your points are taken at each discreet time intervals. Keep in mind that this is an average velocity not the exact velocity, but since the time interval is 0.1 sec, it should be a good approximation. It doesn't mean that right at zero second, the trolly is going 53cm/sec because right at 0sec, it is going 0cm/sec. V=(distance final  distance initial) / (time final  time initial) Thus for the first sample: V0=( 5.3cm  0cm ) / ( 0.1sec  0sec) V0= 53 cm/sec For the second sample: V1=( 11.5cm  5.3cm ) / (0.2sec  0.1sec) V1=62 cm/sec and so fourth for V2, V3, and V4 It works out that: V0= 53 cm/sec V1= 62 cm/sec V2= 101 cm/sec V3= 125 cm/sec V4= 151 cm/sec (verify for yourself) Now that you have the velocities at each time interval, you can find the acceleration: Thus A= (velocity final  velcoity initial) / (time final  time initial) A0=(53 cm/sec  0cm/sec) / (0.1sec  0sec) A0=530 cm/sec^2 The rest I'll leave up to you to do. 3. To find the average, it is easy, just add up all the acceleration points then divide by the number of points you added up. Ave = (K1+K2+...+Kn)/n where n is an integer Ex: Ave = (2+3+1)/3 = 2 4. The graph is telling you the distance traveled compared to the amount of time it took to travel that distance. From this graph acceleration occurs when the distance vs time rises or decreases . If the graph starts to become linear ( the line makes a 45 degree angle to the base of the graph ) then it has stopped accelerating and has constant speed. This is what seems to be happening towards the end of your measurements as friction and drag starts to counter the acceleration due to gravity. Hope this helps a little. What's this project for? 
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Guest_anonymous 
Posted: Jan 25 2006, 05:35 AM


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what is a ticker timer????!! 


bum 
Posted: Jul 23 2006, 07:57 AM

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its kinda hard to explain...... a ticket timer is a device that shows how fast an object is going.... you put the "tape" through the ticket timer and then attach it to an object......after the object has stopped you will see "dots" on the paper, this shows how fast the object has travelled.....the closer the dots r together the slower the object travels...the further the dots are apart the faster the object has travelled.....


jessica 
Posted: Jul 23 2006, 08:00 AM


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thanks~~ that helped!!!! u rock~~~!! 


corey 
Posted: Feb 26 2007, 09:07 AM

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[FONT=Geneva][SIZE=7]
What is the point of doing this experiment? 

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