Part 1: Design
The two main factors that affect an object’s motion are mass and velocity, but there are other factors such as inertia and gravity that also affect it. Inertia is the object’s ability to resist a change in motion and the larger the mass of the object, the greater its inertia. Gravity is another factor that affects motion; it’s the attraction between all matter. Gravity is what pulls objects together, and what keeps us standing on earth. Momentum is the product of mass and velocity, so if you want a greater momentum you either need to increase the object’s mass or its velocity. If there is an increase or decrease on mass or velocity, the momentum will change according to the factor changed. We did a Marble Investigation to test the statement above.
Our aim was: to investigate the effect of marble mass on distance. We predicted that the greater the mass of the marble the further it would go. Our independent variable was the mass because we changed it and the dependent variable was the distance traveled by the marble. Our controlled variables were the point where we dropped the marble on the ruler, and the height of the books was always the same. To make sure this would be the same all the time we started all trials on the beginning of the ruler (0cm), and we used the same number of books every time.
Materials
10 1.5 cm books
30 cm ruler
3 meter sticks
one plastic cup
tape
physics car
plastic cup
2 marbles with different masses (67.0g and 18.7g)
Procedure
1. Set up the experiment.
2. Weigh both marbles and record their numbers.
3. Gently put one of the marbles on the gap of the two meter sticks in order for it to fall and go into the car. Make sure you always put the marble on the same place of the meter stick (0cm).
4. Measure the distance that the physics’ car traveled after the marble went inside it and record the data.
5. Do step #3 and #4 for four more times. (you will have a total of 5 trials, remember to use the same marble for all of its 5 trials)
6. Get the other marble that you have not used and gently put it on the the gap of the two meter sticks in order for it to fall and go into the car. Make sure you always put the marble on the same exact place of the meter stick (0cm).
7. Measure the distance that the physics’ car traveled after the marble went inside it and record the data
8. Do step #6 and #7 for four more times. (you will have a total of 5 trials, remember to use the same marble for all of its 5 trials)
Part 2: Data Collecting and Processing
During the experiment I observed that the two different marbles had very different results. I also observed that while the marble was going down the slope the marble seemed to be going faster. And while the marble was going down the slope it would make a loud noise. Once the marble hit the cup that was on top of the physics car, sometimes the marble would come out of the cup.
Part 3: Conclusion
I discovered that the bigger the mass of the marble the more distance it traveled. For example when the lighter marble (18.7g) hit the cup on the physics’ car, it traveled an average of 16.52 cm, while when the heavier marble (67g) hit the cup on the physics’ car, it traveled an average of 73.32 cm. Since the heavy marble weighs more than 3.5 times than the lighter one, the 67g marble traveled for more than 3.5 times than the 18.7g marble.
Momentum is related to this experiment because momentum has to do with moving objects, its formula is Mass x Velocity. The greater the mass of the object (marble) the more momentum it will have, since you would be multiplying larger numbers. If and object has a greater momentum, it is harder for it to stop, therefore the marbles with more mass took longer to stop, resulting in a larger distance traveled by the car. Just like if a car and a truck were to brake at the same time, the truck would need a larger distance to completely stop, the marble with more mass caused a longer distance traveled by the car. The marble with more mass had a greater impact on the distance traveled by the car. Therefore it is correct to say that the marble with more mass has a greater momentum than the other marble.
Errors
There might have been many errors during this investigation. Fernanda and I would take turns in putting the marble on the slope, and maybe our forces were different so one of us could have applied a bigger force which resulted in the marble traveling further. To eliminate this error, I think that only one person should have been putting the marbles on the slope. Another source of error is that we did not tape the meter stick to the books, we just put the meter stick and we didn’t think there would be the necessity of taping it, since it seemed to be still. But the fact is that even if we didn’t notice, when we put the marbles maybe the meter stick moved and the gap could have become bigger/smaller. Something else me and my group noticed is that when we put the heavier marble and it traveled towards the plastic cup, when it was coming down, the meter sticks started moving apart from each other creating such a big gap between one another, that sometimes the marble would fall without even reaching the cup. To fix this problem, we should have taped the meter sticks to the books, to prevent them from moving. Another observation is that on the graph, we can see the line would not go to 0, so if I had to make this experiment again I would have done more trials to get a more accurate data.
