Part 1
I think that friction, force, distance, and placing of objects affect an object's motion. For example, the material of the street and the car's wheels can affect how fast it goes. The force of the push you give somebody on a swing affects how high and fast she goes. If you place objects in front of an object in motion, it will hit the object and probably stop or decrease speed.
My aim was to see if number of marbles used in the experiment affected the distance that the car travelled.
Independent variable: The number of marbles used.
Dependent variable: I measured the distance the car travelled with one, two and three marbles.
Controlled: I controlled the size of the pile of books, the same car, same ruler to measure, and same rulers for the car to fall down into.
Materials:
1. 4 books
2. 2 rulers (for the marble path)
3. Other rulers (to measure the distance)
4. A car
5. A plastic cub
6. Tape ( to glue the cup on the car)
7. Three marble balls (67.124 g each)
Procedure:
1. Set up one stack with three books, place the 2 rulers side by side, using the books to keep them standing, leaving a small gap in the middle.
2. Set the remaining book at the end of where the two rulers reach.
3. Place the car at the end of the stack with 1 book.
5. Record the distance the car travelled.
6. Repeat steps 4 and 5 using 1, 2 and 3 marbles. Do 3 trials for each marble.
Part 2
Here is a table for the raw data:
Here is a table for the sum of the results:
Observations:
• Maybe during the experiment the placing of the ruler, books, car, etc could have been different then on other trials. That could have affected the final results.
• The position of the rulers used to measure the distance the car went could have a different placing and therefore the measuring of the data could have been altered.
• The force applied to the marbles when they were pushed down the ruler could have affected the distance it went.
Conclusion:
After completing the experiment it is clear that the amount of marbles used greatly affect the distance covered by the low-friction cars. The experiment went as expected, as the momentum that the marbles held moved the car just as predicted. There was one set of anomalous results, as one of the results each distance was about 20-30cm less than the expected displacement. The only errors that could have been made is marbles starting at different heights. This can be fixed if there is a marking on the rulers to show exactly where the marbles must be placed. The same sort of experiment could be expanded into a real life situation as it can be compared to cars with different masses hitting your rear bumper, and how far this would cause you to travel.
The results recorded are trustworthy, as the experiment was repeated three times, but the average would be more accurate if the results of ten experiments would have been taken, which was not the case. Although a low-friction car was used, the marbles used were not completely identical. Some had small chips or bumps, which would have affected how well the marbles rolled and a slight impact on the mass. The rulers were also old and worn-out, which resulted in many chips along the edges. This cause the marbles to slow down a small amount each time it would hit a bump. To improve the experiment, new materials should be used, so there are no mistakes during the experiment. The teamwork was balanced as both group members worked together in the completion of the experiment. This experiment showed that mass truly and greatly affects a car's movement, especially when there is little friction. For further inquiry, greater amounts of marbles should be used, different heights be tested, and different surfaces be tested.
