4000302260centerScience 21 – Term 3 20183300095000Science 21 – Term 3 2018420003175000880009408795PAYNE, MatthewMatthew Payne450000PAYNE, MatthewMatthew Payne420003175000175001870710Factors that affect speed going down an incline plane450000Factors that affect speed going down an incline planeright212598000Contents TOC o “1-3” h z u Abstract PAGEREF _Toc523691189 h 2Introduction PAGEREF _Toc523691190 h 2Methodology PAGEREF _Toc523691191 h 6Results: PAGEREF _Toc523691192 h 7Discussion/analysis of results PAGEREF _Toc523691193 h 8Conclusion PAGEREF _Toc523691194 h 9Appendix/ces PAGEREF _Toc523691195 h 10Table 1 PAGEREF _Toc523691196 h 10Table 2 PAGEREF _Toc523691197 h 11Reference List PAGEREF _Toc523691198 h 12AbstractPhysics is one of the main concepts in the world. Without physics, there would be no knowledge of how rockets, automobiles, simple mechanical devices such as a see-saw, modern communication and natural applications such as our brain automatically use physics to get us through our daily lives. It heuristically solves linear equations to get an idea about the range of the answer and takes decisions based on that. For example, this is our thought process when we are crossing a road. However, when either a car or a trolley is rolling down an incline plane, they would need a certain mass and height for gravity to push the car or the trolley down the incline. If there was no friction, people would not be able to walk, run, write or play sports. Things would continue to move unless they hit anything in their way. Driving to work would be impossible, or anything else that moves in fact, automobiles, ships, and most aircraft would be useless: If you could get them moving, steering would be difficult, and stopping safely would be almost impossible or stop moving.
It would be worse than trying to move around on the wet ice. Everything would have to be tied down. Overall, friction, mass, height and different types of surfaces all depend on going down an inclined plane. This is because some surfaces are smooth which makes the trolley go down faster due to the coefficient of friction, otherwise, if the surface was rough, the friction will become slower and a lot harder to brake. IntroductionThere are 3 types of laws of motion that Newton had discovered in 1687.
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The first law of motion is an object at rest will remain at rest, and an object in motion will remain in motion, at a constant velocity unless or until outside forces act upon it. Examples of this first law in action are literally unlimited. One of the best illustrations, in fact, involves something completely outside the experience of Newton himself such as an automobile. As a car moves down the highway, it has a tendency to remain in motion unless some outside force changes its velocity.
The latter term, though it is commonly understood to be the same as speed, is, in fact, more specific. Velocity can be defined as the speed of an object in a particular direction. In a car moving forward at a fixed rate of 96 km/h, everything in the car such as the driver, passengers, objects on the seats or in the car boot is also moving forward at the same rate. If that car then runs into a brick wall, its motion will be stopped, and quite abruptly. But though its motion has stopped, in the split seconds after the crash it is still responding to inertia, rather than bouncing off the brick wall, it will continue ploughing into it.
The people and objects in the car will continue to move forward in response to inertia. Though the car has been stopped by an outside force, those inside experience that forces indirectly, and in the fragment of time after the car itself has stopped, they continue to move forward, unfortunately, straight into the dashboard or windshield. It now should also be clear from this example exactly why seatbelts, headrests, and airbags in automobiles are vitally important. In everyday terminology, people typically use the word inertia to describe the tendency of a stationary object to remain in place. This is particularly so when the word is used metaphorically as suggested earlier, the concept of inertia, like numerous other aspects of the laws of motion, is often applied to personal or emotional processes as much as the physical. According to the second law, the net force acting upon an object is a product of its mass multiplied by its acceleration. The latter is defined as a change in velocity over a given time interval. Hence, acceleration is usually presented in terms of meters per second per second or meters per second2.
The acceleration due to gravity is 9.8 m per second per second, meaning that as every second passes, the speed of a falling object is increasing by 9.8 m per second.
The second law, as stated earlier, serves to develop the first law by defining the force necessary to change the velocity of an object. The law was integral to the confirming of the Copernican model, in which planets revolve around the Sun. Because velocity indicates movement in a single straight direction, when an object moves in a curve such as the planets do around the Sun, it is changing velocity, or accelerating. The fact that the planets, which clearly possessed mass, underwent acceleration meant that some force must be acting on them such as a gravitational pull exerted by the Sun, most massive object in the solar system. Gravity is, in fact, one of four types of force at work in the universe. The others are electromagnetic interactions and strong and weak nuclear interactions. The other three were unknown to Newton but, his definition of force is still applicable.
Newton’s calculation of gravitational force (which, like momentum, is a subject unto itself) made it possible for Halley to determine that the comet he had observed in 1682 which the comet that today bears his name, would reappear in 1758, as indeed it has for every 75-76 years since then. Today scientists use the understanding of gravitational force imparted by Newton to determine the exact altitude necessary for a satellite to remain stationary above the same point on Earth’s surface. The second law is so fundamental to the operation of the universe that you seldom notice its application, and it is easiest to illustrate by examples such as those above and astronomers and physicists applying it to matters far beyond the scope of daily life. Yet the second law also makes it possible, for instance, to calculate the amount of force needed to move an object, and thus people put it into use every day without knowing that they are doing so.As with the second law, the third law of motion builds on the first two. Having defined the force necessary to overcome inertia, the third law predicts, what will happen when one force meets another force. As the third law states, when one object exerts a force on another, the second object exerts on the first a force equal in magnitude but opposite in direction.
Unlike the second law, this one is much easier to explain in daily life. If a book is sitting on a table, that means that the book is applying a force on the table equal to its mass multiplied by its rate of acceleration. Though it is not moving, the book is subject to the rate of gravitational acceleration, and in fact, force and weight, which is defined as mass multiplied by the rate of acceleration due to gravity are the same. At the same time, the table pushes up on the book with an exactly equal amount of force, just enough to keep it stationary. If the table exerted more force than the book.
In other words, if instead of being an ordinary table and was some sort of inflatable object pushing upward, then the book would fly off the table. There is no such thing as an unpaired force in the universe. The table rests on the floor just as the book rests on it, and the floor pushes up on the table with a force equal in magnitude to that with which the table presses down on the floor. The same is true for the floor and the supporting beams that hold it up, and for the supporting beams and the foundation of the building, and the building and the ground, etc. These pairs of forces exist everywhere. When you walk, you move forward by pushing backward on the ground with a force equal to your mass multiplied by your rate of downward gravitational acceleration.
In other words, this is the same as weight. At the same time, the ground pushes back with an equal force. You do not observe the fact that Earth is pushing you upward, simply because its enormous mass makes this motion negligible, however, it does push. If you were stepping off a small unmoored boat and onto a dock, however, something quite different would happen.
The force of your leap to the dock would exert an equal force against the boat, pushing it further out into the water, as a result, you would likely end up in the water as well. Again, the reaction is equal and opposite but, the problem is that the boat is not fixed in place like the ground beneath your feet. Differences in mass can result in apparently different reactions, though in fact, the force is the same. This can be demonstrated by imagining a mother and her six-year-old daughter skating on ice, a relatively frictionless surface. Facing one another, they push against each other, and as a result, each moves backward. The child, of course, will move backward faster because her mass is less than that of her mother. Because the force they have is equal, the daughter’s acceleration is greater and moves farther. Ice is not a perfectly frictionless surface, otherwise, skating would be impossible.
Likewise, friction is necessary for walking, as you can show by trying to walk on a perfectly slick surface. For example, a skating rink covered with oil. In this situation, there is still an equally paired set of forces and your body presses down on the surface of the ice with as much force as the ice presses upward but, the lack of friction impedes the physical process of pushing off against the floor. It will only be possible to overcome inertia by recourse to outside intervention, as for instance if someone who is not on the ice tossed out a rope attached to a pole in the ground.
Alternatively, if the person on the ice were carrying a heavy load of rocks, it would be possible to move by throwing the rocks backward. In this situation, you are exerting a force on the rock, and this backward force results in a force propelling the thrower forward. This final point about friction and movement is an appropriate place to close the discussion on the laws of motion. Where walking or skating is concerned and in the absence of a bag of rocks or some other outside force, friction is necessary to the action of creating a backward force and therefore moving forward.
On the other hand, the absence of friction would make it possible for an object in the movement to continue moving indefinitely, in line with the first law of motion. In either case, friction opposes inertia. The fact is that friction itself is a force.
Therefore, if you try to slide a block of wood across a floor, friction will stop it. It is important to remember this, in case you fall into the mistake that Aristotle’s thinking and so, he confused the world for many centuries. The block did not stop moving because the force that pushed it was no longer being applied, it stopped because an opposing force, friction, was greater than the force that was pushing itAn inclined plane, also known as a ramp, is a flat supporting surface tilted at an angle, with one end higher than the other.
There are certain factors, which affect the stopping distance of a trolley such as gravity and the surface area, which it travels on. If the gravity is decreased, this would affect the friction between the trolley and surface area and so it would decrease the stopping distance of a trolley. Different surfaces are harder for the trolley to overcome.
For example, sand is rough and has a greater resistance, so the trolley would need more energy to travel over sand than a smooth surface. Sand is rough due to the rocks, minerals and the grains in sand. However, if you water on sand, the grains stick and holds its shape. If you add water, it will make the sand more rigid, and the heaps decreased in size until there is no heap. Therefore, a lower applied force is needed to reach a steady state. There are two forms of energy relating directly to the trolley rolling down the ramp. These factors are called potential and kinetic energy. When we’re above the Earth’s surface we have potential energy.
This is called gravitational potential energy. The amount of gravitational potential energy an object on Earth has depends on the object mass and the height above the ground. Gravitational potential energy (GPE) will be present because the trolley will be starting above the ground. On Earth, the force of gravity pulls down on all objects so the GPE would be the force that moves the trolley. However, as it rolls down the ramp the GPE will decrease because its height off the ground is decreasing. At the same time, kinetic energy (KE) will be increasing as the trolley goes down the ramp.
Kinetic energy is the energy of motion. When an object has motion, whether it is either vertical or horizontal motion, it has kinetic energy. There are many forms of kinetic energy such as vibrational (the energy due to vibrational motion), rotational (the energy due to rotational motion), and translational (the energy due to a motion from one location to another). At the top when the trolley is stationary, it will have no kinetic energy because it will not be moving. However, it will gain kinetic energy when it goes down the ramp because it will go from being motionless to moving and increasing in speed. Still, along with gravity and the lines of energy, there is still the problem of energy being lost as the trolley travels down the ramp.
The GPE turns to KE as the trolley goes down, however, all the energy may not be converted into KE. Some energy may be lost to the atmosphere by heat and sound, although, there will be not that much as a difference. The trolley will probably accelerate as it goes down the ramp, so the length of the ramp will have an effect on the speed of the trolley, that is if the trolley does not reach its top speed by the time it has gone down the ramp. More importantly is the influence of the height of the ramp.
GPE = mass x gravity x height so if the height of the ramp is increased then so will the GPE. This, in turn, will affect the KE.Another main factor is the friction that will occur when the trolley rolls down the ramp. Friction is the resistance to motion of one object moving relative to another. It is not a fundamental force, like gravity or electromagnetism. Instead, scientists believe it is the result of the electromagnetic attraction between charged particles in two touching surfaces.
If there was no air resistance or friction, then all objects would accelerate downwards at the same rate. This can be proved by a famous experiment by Galileo, which he is supposed to have done from the leaning tower of Pisa. He dropped a heavy stone and a light stone simultaneously and they both accelerated at the same rate and landed at the same time. However, the trolley will have friction acting on it between the wheels of the trolley and the ramp. The trolley will only be able to move if the force pushing it overcomes the friction acting against it. This means that some of the GPE will be lost towards countering the friction and so the KE will be reduced as friction increases. Since friction is acting on the trolley then the mass of the trolley will have an effect too. Increasing the mass of the trolley would increase the GPE, however, the increased mass at the same time would also increase friction since the pressure between the trolley wheels and the ramp will be greater.
Since these two opposite forces are increasing all at once they may even cancel each other out, therefore the effect of the mass on energy lost being neutralised, but still increasing the net speed of the trolley.Subsequently, I can now say that the speed of the trolley will be proportional to the square root of the height of the ramp. However, as I discussed in my introduction, no system is perfect, which means that energy can be lost from the system. So the KE is most likely to be very slightly lower than the GPE.
It will only be slightly lower because energy can only be lost through heat produced from friction and through sound. The sound energy will be very low, and friction may not be too great because the smooth wheels will be rolling down a smooth surface reducing the friction than if there were rubber wheels on a textured surface.MethodologyThe aim of investigation:I believe that as the height of the ramp increases, so will the speed of the trolley rolling down will increase. This is because, if GPE increases, the trolley rolls further down the ramp, the kinetic energy will be increasing resultantly the speed of the trolley increases. Variables (independent variable, dependent variable)The independent variable: This is the factor that is being manipulated in the experiment. The Independent variable was that we kept the same distance and ramp.
The dependent variable: This is the variable being tested and measured. The dependent variable that our group was changing the height of the trolley and the amount of mass that is on the trolley.Equipment:1x measuring tape, 4x wooden blocks, 1x 975g trolley, 1x 3m wooden ruler, 1x stopwatch, 1x 500g of weights, 1x 100m board, 1x duct tape. Variables: Height, weights, distance, acceleration.Procedure:The group had removed all the required equipment above on the trolley and the equipment was placed on the ground in the classroom where no one would trip over it. The group grabbed the 4 wooden blocks and stacked them against the wall with the 100m bored on top. One person would grab the end of the measuring tape and hold it against the side where the wall is on the board and the person with the measuring tape will measure to 4m. The person with the measuring tape then placed their end down and then grabbed the 3m ruler and placed it on top of the 4m on the measuring tape.
When everything was ready, the person who was holding the end of the tape against the wall had placed the end on the ground and not in the rampway. The group had then grabbed the stopwatch and that same person was standing on the 3m ruler to make sure that the trolley did not move the ruler and the measuring tape. The other person would then grab the trolley and put it on the 100m board and start to count down from 3 to 1 then they would say go. The countdown was to ensure that the person who was standing on the ruler was ready to record the time as soon as the person releases their hand from the trolley. When this happened, the person who was recording the time had to make sure that the trolley had hit the ruler so that person can stop the time. The group then recorded the time and repeated it for 5 trials.
When the 5 trials were completed, the group would then grab duct tape and 4x 50g weights and put them on the trolley. The duct tape was to ensure that the weights do not fall off, so the group gets real data and not incorrect data. The group had then grabbed the stopwatch and that same person was standing on the 3m ruler to make sure that the trolley did not move the ruler and the measuring tape. The other person would then grab the trolley and put it on the 100m board and start to count down from 3 to 1 then they would say go. The countdown was to ensure that the person who was standing on the ruler was ready to record the time as soon as the person releases their hand from the trolley. When this happened, the person who was recording the time had to make sure that the trolley had hit the ruler so that person can stop the time. The group then recorded the time and repeated it for 5 trials.
After the 1075g trials were done, the group had added 4 more 50g weights and duct taped them to the trolley. We then repeated this step above and recorded 5 more trials. ConstantsThe constants are the ramp, the trolley, weights and the blocks.Results: Talk about what this graph isTalk about what this graph isTalk about what this graph isDiscussion/analysis of resultsThe mass of the trolley and the distance that the trolley travels constantly so that the group can focus directly on the effect that the height of the ramp has on the speed. The mass of trolley can affect the force pushing the trolley and the distance travelled would affect the average speed. If the group had altered the mass of the trolley, then we will not be able to distinguish which factor between that and the height of the ramp are the cause of the change in the force behind the trolley.
Similarly, if we change the distance that the trolley has to travel each time, then additional limiting factors may be introduced such as deceleration owing to friction.PredictionBased on the facts that I know regarding the factors affecting a trolley rolling down a ramp, I believe that as the height of the ramp increases, so will the speed of the trolley rolling down will increase. This prediction has been derived from the theory that the kinetic energy of the trolley at the bottom of the ramp (when it is at its fastest) will be inversely proportional to the gravitational potential energy of the trolley (at the top of the ramp to begin with). In other words, as the GPE decreases as the trolley rolls further down the ramp, so the kinetic energy will be increasing, and resultantly the speed of the trolley increases.
If the trolley starts at a height of x, then the GPE will be:mass of trolley x force of gravity x height (x)The KE will be equal to the GPE because the energy will have been transferred through the system. With this in mind, if the height of the ramp is then increased to 2x then the GPE will be doubled, and so the kinetic energy will double. In addition to this I can make a prediction mathematically using the following formula:GPE = m x g x hKE = 1/2 x m x v2? m x g x h = 1/2 x m v2g x h = 1/2 x v22 x g x h = v2v = ?2ghFrom my preliminary results, I have found that the height of the ramp does affect the speed of the trolley but, the higher the ramp is, the faster the trolley will travel.
This backs up my prediction and my hypothesis, which I had made earlier, and I can relate my conclusion to my scientific knowledge because I already know that when the trolley is placed at the top of the ramp, it has a certain amount of gravitational potential energy, which is then converted into kinetic energy when the trolley travels down the ramp. So, the higher the ramp is, the more gravitational potential energy there will be to be converted into kinetic energy, resulting in more kinetic energy making the trolley travel at a faster speed. Some improvements that could have been better is that, when the group was saying go, there was some delay in pressing start on the stopwatch. This makes the time inaccurate a little bit depending on the delay that the stopwatch was started. When the group had the weights on the trolley, the first 2 trials for the height being 15cm, some of the weights had fallen off so the mass wasn’t the same all around. To fix this issue, we should have had put tape on the weights and taped it to the trolley, so the weights do not move.
Sometimes it looked like the trolley was trying to go off the board which the wheel could of went off which makes the trolley to slow down which insults in timing badly but not only that, the trial would be restarted. The blocks that were used for the height and the 100m board was stable and did not move while the trolley was rolling down. There was no other issue apart from knowing when to time and when to stop the time when it had approached 4m.ConclusionThe actual method of executing the experiment required for this investigation was possibly difficult. In undertaking the process, I did encounter minor difficulties, however, to my relief, there were no substantial intricacies involved and on the whole, the operation ran smoothly. The most significant problem that I had was trying to keep the trolley from straying off its course, which ideally should be a perfectly straight line down the ramp. This obstruction could have played some part in influencing the results.
If when the trolley did not roll down in a straight line, then there could have been a chance that there was a convergence between the weights falling off if they had no tape on them and the timing can be inaccurate. The reliability of the experiment to deliver conclusive results is also questionable. The set-up involves numerous timings and making sure that the weights did not come off the trolley that could be substituted with more precise solutions with a revised experimental method. In extension to this investigation, I could explore the effects that other factors have on the speed of the trolley. Overall, the hypothesis, I believe that as the height of the ramp increases, so will the speed of the trolley rolling down will increase is correct because, if you look in the appendix at Table 1 and Table 2, all my working out is there and the results.
When we added more mass to the trolley, the trolley acceleration was a lot faster and the time had decreased. The velocity had increased due to the weights and the height (as seen in table 2). They would probably all tie in with the theory of GPE changing to KE such as varying the mass of the trolley or carrying out the experiment in a different way such as putting sand, rock, gravel, rubber and or oil on the 4m board and see the friction caused by them if possible. Appendix/cesTable 1Height (CM) Trolley Mass (Grams) Distance (Metres) Average time(Seconds) Acceleration (m/s2) Velocity (m/s) GPE (Joules) Kinetic Energy (Joules)15cm 875g 4m 3.176s 0.
393m/s2 1.25m/s 128.625J 683.593J 15cm 1075g 4m 2.88s 0.479m/s2 1.38m/s 158.025J 1023.
615J 15cm 1275g 4m 2.86s 0.486m/s2 1.39m/s 187.425J 1231.713JM = 875, H = 15cm, G = 9.8 M = 1075, H = 15, G = 9.8 M = 1275, H = 15, G = 9.
8GPE = M X G X H GPE = M X G X H GPE = M X G X H875 X 9.8 X 15 1075 X 9.8 X 15 1275 X 9.8 X 15 = 128.625J = 158.025J = 187.425J KE = ½ x m x v² KE = ½ x m x v² KE = ½ x m x v² KE = ½ x 875 x 1.25² KE = ½ x 1075 x 1.
38² KE = ½ x 1275 x 1.39²KE = 437.5 x 1.25² KE = 537.5 x 1.38² KE = 637.5 x 1.39²KE = 683.
593J KE = 1023.615J KE = 1231.713JV = Distance / Time V = Distance / Time V = Distance / TimeV = 4 / 3.176 V = 4 / 2.88 V = 4 / 2.86V = 1.25m/s V = 1.38m/s V = 1.
39m/sA = ?v / ?t A = ?v / ?t A = ?v / ?t= (vf – vi) / (tf – ti) = (vf – vi) / (tf – ti) = (vf – vi) / (tf – ti)= 1.25 – 0/ 3.176 – 0 = 1.38 – 0/ 2.88 – 0 = 1.39 – 0/ 2.86 – 0= 1.25/ 3.
176 = 1.38/ 2.88 = 1.39/ 2.86A = 0.393m/s2 A = 0.479m/s2 A = 0.486m/s2Table 2Height (cm) Trolley Mass (Grams) Distance (Metres) Average time(Seconds) Acceleration (m/s2) Velocity (m/s) GPE (Joules) Kinetic Energy (Joules)21cm 875g 4m 2.
48s 0.649m/s2 1.61m/s 180.075J 1134.04J21cm 1075g 4m 2.418s 0.
682m/s2 1.65m/s 221.235J 1463.34J21cm 1275g 4m 2.46s 0.658m/s2 1.
62m/s 262.395J 1673.06JM = 875, H = 21cm, G = 9.8 M = 1075, H = 21, G = 9.8 M = 1275, H = 21, G = 9.8GPE = M X G X H GPE = M X G X H GPE = M X G X H875 X 9.8 X 21 1075 X 9.8 X 21 1275 X 9.
8 X 21 = 180.075J = 221.235J = 262.395J KE = ½ x m x v² KE = ½ x m x v² KE = ½ x m x v² KE = ½ x 875 x 1.61² KE = ½ x 1075 x 1.65² KE = ½ x 1275 x 1.62²KE = 437.5 x 1.
61² KE = 537.5 x 1.65² KE = 637.5 x 1.62²KE = 1134.04J KE = 1463.34J KE = 1673.
06JV = Distance / Time V = Distance / Time V = Distance / TimeV = 4 / 2.48 V = 4 / 2.418 V = 4 / 2.
46V = 1.61m/s V = 1.65m/s V = 1.62m/sA = ?v / ?t A = ?v / ?t A = ?v / ?t= (vf – vi) / (tf – ti) = (vf – vi) / (tf – ti) = (vf – vi) / (tf – ti)= 1.61 – 0/ 3.
176 – 0 = 1.38 – 0/ 2.88 – 0 = 1.39 – 0/ 2.86 – 0= 1.61/ 2.48 = 1.65/ 2.
418 = 1.62/ 2.46A = 0.649m/s2 A = 0.682m/s2 A = 0.658m/s2Reference Listhttp://www.
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