Sir Isaac Newton’s second law describes how the mass of an object changes the way that it moves when acted upon (Jacplus 2013). This means that the more mass that an object has, the harder it will be to move. Mass can be calculated using the formula: F=ma
* Where: F is the force (N)
* m is the mass (kg)
* a is the acceleration (m/s/s)
If there are two balls and one has a mass of 1kg and the other has a mass of 2kg, then the ball that has a larger mass will be harder to push. This concept is used in modern day equipment. An example is a race car mechanic. He will have to make the car as light as possible. This is to ensure that the engine isn’t moving anymore mass than it has to and achieve maximum acceleration. This outcome can be changed by friction. Using the race car example, if the road is really smooth than the car will travel along it easier as the car has no extra resistance. This concept can also work the opposite way. If the road is rough then the car will require more power to move (Physics4Kids 2012). Gravity is a force that pulls an object towards the centre (Free dictionary 2012). An example of this is occurring is on earth and other planets. When we jump we immediately fall back down. This is due to gravity. The force of gravity can change depending on the planet. On earth the force of gravity is 9.8m/s. This means that for everyone second you fall you will travel 9.8 meters. The force of gravity is different on other planets. Gravity is stronger on earth as it is larger than the moon. On the moon, the force of gravity is weaker and objects will fall for a longer period of time. On the moon the force of gravity is 1.6m/s (How Stuff Works 2013). The larger an object is, the greater its force of gravity. Gravity also occurs on the smallest of atoms. Tiny electrons are pulled towards the nucleus of the atom and then form an orbit around it. This is the same as the earth and the moon. The moon is the electron and the earth is the nucleus. The moon is pulled into orbit around the earth just like the electrons.
To prove the credibility of Newtons 2nd law
The car that has the most amount of mass will move the slowest and the car with the mass will move the quickest.
The mass of the cars
How quickly the car will move
The weight of the car that is being pulled
1. A start and finish line for a car was marked out on a table 2. The car was placed on the start line
3. A 100g weight was attached by string to the car
4. The weight was then dropped off the table and the time for the car to move from the start to finish line was recorded 5. The test was then set up again but there was an extra 500g weight on top of the car 6. The time was then recorded again
7. An extra 1kg grams was added to the car (now 1kg)
8. The time was then recorded again
Weight 1 : 0g| Weight 2 : 500g| Weight 3 : 1kg|
0.98sec| 1.28sec| 1.75sec|
0.97sec| 1.31sec| 1.69sec|
0.97 average| 1.29 average| 1.72 average|
These results show that Newtons 2nd law of physics is true as is my hypothesis. The car with the most weight took the longest to fall and the car with the least weight the quickest. The car with the most weight took an extra 0.75 seconds to fall compared to the quickest car. During the setup of the experiment there was discussion over how to keep the force of the car constant. There was the idea that they would be all pushed at once with one big block. This appeared too complicated as there were different variables and changes that could occur. The second idea was to strap the car to a 1kg weight and drop it. This method was agreed on and used. The force of gravity is constant and the weight would fall at exactly the same speed every time. There was some discussion over how to keep the friction the same for each piece of rope that we used. This was easily resolved as the car being used was in the exact same place and the pulley being used was the same. This meant that the friction would be the same the whole time. Conclusion
Newtons 2nd law is correct as it my hypothesis. This is that the greater the mass of an object the harder it will be to move. This was proven as the car with the least weight moved the quickest, and the care with a 1kg on it the slowest.
Physicsclassroom.com (1996). Newton's Second Law. [online] Retrieved from: http://www.physicsclassroom.com/class/newtlaws/u2l3a.cfm [Accessed: 30 Jul 2013]. Content.jacplus.com.au (2000). Science Quest 10 Australian Curriculum Edition eBookPLUS (INST LIC) - 08 Forces, energy and motion - 8.5 SCIENCE UNDERSTANDING: Newton's Second Law of Motion. [online] Retrieved from: http://content.jacplus.com.au/faces/pages/ebookviewer.xhtml?isbn=1742461492[Accessed: 30 Jul 2013]. Dictionary.com (2013). the definition of gravity. [online] Retrieved from: http://dictionary.reference.com/browse/gravity [Accessed: 1 Aug 2013]. Layton, J. (2000). HowStuffWorks "How does gravity work?". [online] Retrieved from: http://science.howstuffworks.com/environmental/earth/geophysics/question232.htm [Accessed: 10 Aug 2013]. Physics4kids.com (1997). Physics4Kids.com: Motion: Friction. [online] Retrieved from: http://www.physics4kids.com/files/motion_friction.html [Accessed: 10 Aug 2013].