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Travelling down a ramp

Factors such as; type of surface of ramp, height of ramp, weight/mass of trolley and the gradient or angle of a ramp all affect the speed of a trolley as it travels down a ramp. For instance a trolley may accelerate faster down a ramp on smooth wood rather than on carpet because carpet might provide greater friction for the tyres rather than the smooth wood. Out of all these factors, I am going to pick just 1 factor and alter it 5 different times, doing 3 trials for each time. We have also done some preliminary work on ticker - timers, so in my investigation I am going to expand on the notion of ticker - timers and incorporate my knowledge of ticker - timers in to this investigation.

Aim: To investigate the relationship between the speed of the trolley as it travels down the ramp and the gradient of the ramp.coed ed" . "r se" . ed . "ed" . "w or". ed . " " . ed . "k ined foed " . ed . ":

Hypothesis: I believe that the speed of the trolley travelling down the ramp will increase as the gradient of the ramp is increased. This is because of several different factors.

One of these factors is Potential energy. Potential energy is stored energy possessed by a system as a result of the relative positions of the components of that particular system. In this case, it is a trolley that is held at the top of the ramp, which is above the ground; the trolley and the earth possess a certain amount of potential energy. In this experiment we are focusing on a particular type of potential energy, gravitational energy.

1. After each experiment we cleaned the ramp with a cloth, to make sure that there was

no dirt which could affect the speed of the trolley as it travelled down the ramp.

2. Before we let go off the trolley, I held the ramp so that it would not tilt and therefore

it would not interfere with the speed of the trolley as it travelled down the ramp.

These above factors will also give me more accurate and reliable results. People consider accurate and reliable results as the same kind of result but it is not. Accurate results are results, which are right or correct results. A reliable result means, every time you carry out the experiment they are almost identical results. For example a normal weighing scale might give you reliable results, which gives you the same results each time you do the experiment but they are not as accurate as if you measure with a digital scale. I believe that my results are reliable but not accurate because we had limited resources to carry out the experiment with. Looking at my results they do follow a pattern and a trend. Both the potential and kinetic energy go up as the height increase but more potential than kinetic. The acceleration of the trolley is more than the speed of the trolley and both the kinetic energy and acceleration graphs are almost identical. I have no anomalous results but two inaccurate results, which do not fit in with the rest of the attempts at the same heights. This may have happened because the person timing the trolley may have pressed the digital stopwatch's stop button too late.

Height (cm)

Reading 1

Reading 2

Reading 3

Average

Average Speed (cm/s)

12

1.011

1.078

1.007

1.032

67.83

14

0.913

0.905

0.936

0.918

76.25

16

0.818

0.847

0.835

0.833

84.00

            I feel that overall the results were quite accurate. This is can be seen when looking at the graphs, which show a straight line with all of the points apart from one or a few being very close to or on that line.

            The reasons for these few inaccurate results may have been as followed:

∙The trolley may have been pushed slightly at the beginning therefore giving it an advantage.

∙The apparatus might not have been set up correctly meaning that results could have been abnormal.

∙The height of the trolley might not have been measured correctly and therefore, with a greater height, the trolley would have gone faster with a lower time.

            As there were only three anomalies, I can say that the results obtained are reliable to the extent that a clear conclusion can be made from them. I believe that the results obtained do strongly support my conclusion and that further results do not need to be taken apart from the three anomalies which should be repeated.

Further work:

            In addition to the experiment, further work does not need to be done. However to obtain more evidence to support my predictions and possibly to make another prediction, I would also vary another variable. The variable I would choose to vary would add a weight to the trolley pulling it down the ramp. This would speed it up and I would vary the amount of weights. To obtain good results I would drop the weight down onto the floor from a string attached to the trolley with the help of a pulley. With more weights, I would predict that the trolley would go faster down the slope and therefore there would be a lower time.

suhura. Thus, we can say that whilst this represents a progression, in the end we have come no closer to any "real" knowledge.

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