# Physics Coursework

Extracts from this document...

Introduction

Conclusion on the distance travelled by the car to the height up the ramp

From the pattern on the graph we can conclude that the distance travelled by the car is further when you put the car higher up the ramp. We can prove this from the results on the graph. At ten centimetres up the ramp, the car travels an average distance of one hundred and seven point three centimetres. This is quite a low average of distance travelled and that is because there is less gravitational potential energy. As we get higher up the graph we find that the average distance does get larger, this is because there is more gravitational potential energy, and at twenty centimetres up the ramp there is almost a ninety centimetre difference of average between the lowest average and the highest average. This is because there is the most gravitational potential energy for the car.

From the graph we can see that the gradient is larger at points fifteen centimetres on the average to fourteen centimetres on the average, then at seventeen centimetres on the average to twenty centimetres on the average. This because the car is starting to reach its terminal velocity

Middle

Half x Mass x (Velocity) squared = X amount of J

Multiply both sides by 2: Mass x (Velocity) squared = 2 x X amount of J

Divide both sides by the Mass: (Velocity) squared = 2 x X amount of J

Mass

Velocity = The square root of: 2 x X amount of J

Mass

Explanation of my conclusion

The results of the graph should be a straight line through each average and the error bars should be fairly small. This is because in the experiment the factors for each point should each point should be the same apart from the variable that I am changing and the distance travelled. The distance of the car is affected by the gravitational potential energy, which then changes into kinetic energy, the friction and the work done of the car. As the car comes down the ramp it should keep on gaining more and more speed due to the gravitational potential energy that the car has until it reaches its terminal velocity. Then as the car comes off the ramp the energy is converted into kinetic energy and the ground should starts to apply friction to the work done by the car and eventually slows the car down. The friction that is applied should be the same each time if the car goes down the same surface each time.

Conclusion

Reliability

Because there are twenty outliers in my data and the range of the repeats is large, I am not confident in my conclusion. The scatter of the graph should have been a straight line going up because the results should have been directly proportional. The results from my test are unreliable because of the large range of the repeats. The apparatus was not very accurate and that would have affected the reliability of my results, this would explain the scatter of the graph. I would have been more confident in my results had I used the apparatus that I have described because I believe that I would have had a more accurate apparatus and therefore more reliable results. I would have been more confident in my results had my technique been better, but if I had used the technique and apparatus I described in my evaluation making sure that all the factors that could affect the distance that the car travelled were controlled properly, then I would be more confident in the results that I have got.

This student written piece of work is one of many that can be found in our GCSE Forces and Motion section.

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