Find the relationship between the angle of incidence and angle of refraction for light passing from air to Perspex.
MYP Physics Practical - Refraction Aim: To find the relationship between the angle of incidence and angle of refraction for light passing from air to Perspex. Apparatus: Raybox, 12V supply, Perspex block, 30cm ruler, protractor Data Collection: Tries Incident Angle (Degrees) Refracted Angle (Degrees) 0 0 2 2 8 3 36 23 4 47 29 5 58 34 6 80 41 Data Processing: Incident Angle (i) (Degrees) Refracted Angle (r) (Degrees) Sin of Incident Angle (i) Sin of Refracted Angle (r) Refractive Index (Sin i/Sin r) 0 0 0 0 0 2 8 0.2079 0.1392 .49 36 23 0.5878 0.3907 .50 47 29 0.7314 0.4848 .51 58 34 0.8480 0.5592 .51 80 41 0.9848 0.6561 .50 Conclusion: Looking at the graph on the previous page we can see a best-fit line drawn on the graph by the computer. In order to move forward and find out whether there is a relationship between sin (i) and sin (r) it is necessary to find the gradient. Below I have found the gradient: Gradient = rise/run Gradient = 0.5878 - 0.2074/0.3907 - 0.1392 Gradient = 1.51 This gradient I have found which is 1.5, suggests that as the sin (r) increases the sin (i) also increases in the ratio of approximately 1.5. The data table in the data processing section tells us that most of the ratio is around 1.5 as written under the column of refractive index. Refraction can be seen in many public areas
Physics Laboratory - "Waves in Strings".
Dmitri Ramzaitsev 30.11.03 11B Physics Laboratory - "Waves in Strings" Data Collection The Harmonic Number 2 3 4 5 The Number of Nodes 2 3 4 Mass Pulling the String (in Kg) 0.3 0.1 0.030 0.015 This data does not include any uncertainties purposely. While the experiment was carried out, I noticed that the number of harmonics was not so clear every time. The mass at the end of the string could be change to ± 0.015 kg and we could not see any difference in the number of nodes. The additional mass simply displaced the nodes a little, but created none. Therefore, it is safe to say that there was no specific or accurate mass that we measured to create each harmonic. And because the masses that we used were accurate to the nearest gram, it is not necessary to include ± 0.0005 kg of and uncertainty since it does not make the experiment any better. Data Processing and Presentation A. 1.), 3.), 4.) g = 9.81 m/s2 mg = weight The Harmonic Number 2 3 4 5 Mass used in Kg 0.3 00 0.100 0.030 0.015 Gravitational Force of Mass in Newtons 2.94 0.981 .294 0.147 The Square Root of Force (to 3 s.f.) .72 0.990 0.542 0.383 The Inverse of the Square Root of Force (to 3 s.f.) 0.582 .01 .84 2.61 2.), 5.) See attached sheets please. B.1.) There is a clear relationship between the number of harmonics and the force pulling on the string. As the
Forced vibrations, resonance and damping.
Experiment 2: Forced vibrations, resonance and damping. Diagram: Method: We will set up the above diagram using the apparatus and once we have done this we will make sure that everything is working the way it should be. This is because the Edspot light beam galvanometer is an expensive piece of equipment and can be ruined if the circuit is not correctly set up. After this has been done we will carry on with the experiment, we will set RA as close as we can to 100k and to check this we will use a multimeter. This part of the circuit will not be altered. The resistance box will be set to 3000 Ohms but this will be changed throughout the experiment. This resistance box varies the amount of electromagnetic damping to the set figure. Once we have done this we will then record the time it takes for 20 oscillations to occur and then calculate the time for one oscillation. Then using this we cam calculated the natural frequency of oscillation of the coil. For each setting, we will then recorded the amplitude of the oscillations shown on the galvanometer. Once this was all done we began our experiment and we can change the frequency on the signal generator and recorded the amplitude. Below are the results from the experiment. Results: RA, which controls the amplitude of the oscillations, was set to 97.7 K?, which is measured using a multimeter. For 20 oscillations to occur it
Factors Affecting The Strength of An Electromagnet
Factors Affecting The Strength of An Electromagnet Aim To find out the factor affecting the strength of an electromagnet when picking up paper clips. The idea was to count the paper clips that the electromagnet picked up. Predictions First of all, an electromagnet has to be defined. An electromagnet can also be called a Solenoid. An electromagnet can consist of just one wire, but usually an electromagnet is made up of wire coiled around a soft ferromagnetic core (a solenoid). This extract comes from the book ' The Working World of Physics', " Those like Iron, Nickel and Cobalt which are easily magnetised are called Ferromagnetic." Materials that only react in a very strong magnetic field are called Paramagnetic. What I think will happen is the current will flows through the wires of the solenoid and which will creates a magnetic field. By introducing more current, the magnetism will increase. I also think more and more domains in magnetism will increase the magnetism in the core. The reason why I think this will happen is because solenoid are electromagnets and they creates magnetic fields when current flows through them which mean when the current increase then the flow of the current will increase the magnetism in the coil of wire. Equipment This is the list of the apparatus I will need and why it is needed: Variable resistor: -Fine control Ammeter: -Control
Are mobile phones dangerous? Research Project.
Are Mobile Phones Dangerous? Introduction I am looking at ‘Are mobile phones dangerous?’ The case study has some relevance to the current news topics because the findings have been made public and people are always asking ‘are there any risks’, as you will find out there are many theories and supposed evidence, that may or may not be reliable. In this study I will be looking for a correlation between mobile phone usage and fertility in men, increased risk of brain tumours and other negative side effects such as concentration levels. Background information: (information from http://www.vodafone.com.au/personal/aboutvodafone/healthmobilephonetechnology/howdoesthemobilephonesystemwork/index.htm ) Mobile phones use radio waves however some have a higher frequency so can be classed as microwaves. Radio waves are used for communication. Long wave radio has lengths of about 1km. Mobile telephones are two-way radios. When you talk into a mobile telephone, it picks up your voice and converts the sound to radiofrequency energy (or radio waves). The radio waves travel through the air until they reach a receiver at a nearby base station. The base station then sends your call through the telephone network until it reaches the person you are calling. When you receive a call on
Making Sense of Data.
Making Sense of Data A loudspeaker is held over a glass tube, one end of which is submerged in water. The frequency from the signal generator is set, and the tube is moved until it resounds at the fundamental frequency, causing a raise in volume. This raise in volume is caused by the manner in which the sound waves travel through the tube. The wave travels down the pipe, is reflected off of the water, and leaves the tube. There is a node at the closed end, as the air in contact with the water is permanently at rest, and an anti-node at the end of the pipe, where the air is free to vibrate. The combined effect of the two waves creates a standing wave. The amplitudes of both waves are added together, thus making the overall amplitude bigger. Therefore, we hear an increase in volume when the waves are superposed. These vibrations extend a little out of the edge of the tube. The distance extended, or end correction (c), is directly proportional to the radius of the pipe: c = 0.58 × radius You can also find the end correction by constructing the graph with the reciprocal of the frequency against the length of the pipe. The difference between zero and the point at which the trend line crosses the x-axis will give you the end correction of the pipe. This is the equation of the trend line. = 0.0118 + 0.0001 Therefore, when = 0: Hence, the end correction of
Electromagnetism Investigation
G.C.S.E SCIENCE COURSEWORK BY JENNA DAWSON Electromagnets We will be measuring the distance of a compass attracted to the electromagnet. We will change the amount of turns on the coil. Research An electromagnet is a coil of wire. An electric current within the coil creates a magnetic field. The field can be made stronger by winding the wire round a piece of iron, increasing the amount of turns on the coil or increasing the size of the current flowing through the coil. Electromagnets are far more useful than permanent magnets because: they can be switched on and off, the strength of the magnetic field can be changed by altering the current and they can easily be made into a variety of shapes and are less expensive to make. Variables Independent Variables * Strength of electromagnet (changing the amount of turns on the coil) * Size of compass * Coating on wire (PVC) * Thickness of wire * Size of voltage - 12V * Type of nail Dependent Variables * Distance from electromagnet to the object. We will be measuring the distance of a compass attracted to the electromagnet. We will change only the amount of turns of the coil. We have chosen this because it the easiest variable to change therefore our results will be more precise. Prediction I predict that the more turns on the coil, the stronger the magnetic force, the further the compass will be. I base this
Investigation Into How the Depth of Water Affects the Speed of a Wave.
INVESTIGATION INTO HOW THE DEPTH OF WATER AFFECTS THE SPEED OF A WAVE Aim To find how the depth of water affects the speed of a wave. Waves are vibrations (or oscillations) moving through something - a medium. As a wave passes, each bit of the medium vibrates in turn. The vibrations appear to move through the medium. Each bit of the medium in turn vibrates/oscillates, but stays where it is. The wave transfers energy as it moves. The medium can be matter (solid, liquid, gas). This is the case for water waves. There are two types of wave: a) Transverse waves. The vibrations are at right angles to the direction of the wave. b) Longitudinal waves. The vibrations are along the same direction as the waves. The waves I will be studying are transverse waves. During a previous experiment I found that a drop height of 5cms and to allow the wave to do 3 laps of the container before stopping the stopwatch was the best course of action. 5cms is a good height because it is high enough to cause a strong wave, but not high enough to create water to spill over the container's edge. I chose 3 laps because after that the wave starts to lose momentum and slows down. Apparatus Container 1 Ruler Water 1 Stopwatch Prediction I predict that the greater the depth of water, the faster the waves will travel. The reason for this is that when the water is shallow, the container
