323 results found

#### Power Lab - In the power lab, are group thought that Eric would do the most work because he has the most mass and thought that Ashley would do the least work because she had the lowest mass.

Ben Fitzgerald 9/21/09 Mr. Thorndike Power Lab Hypothesis: In the power lab, are group thought that Eric would do the most work because he has the most mass and thought that Ashley would do the least work because she had the lowest mass. We guessed that Ashley would generate the most power because she had to work harder than Eric who we thought would produce the least amount of energy. As we added the books to the current mass of our bodies, it required more work. Machines would be more efficient than humans when it comes to using energy. We guessed that we would have to eat a little amount of food to be able to climb the stairs with books, we guessed that Ashley would need one piece of cereal, I would need a piece of bread and Eric would need a granola bar. These estimations were guess to how well we would do in the power lab exercise. Procedure: . Obtain four books from Mr. Thorndike 2. Go to the staircase under Mr. Thorndike's room between the 2nd floor and the 1st floor mezzanine 3. Have Ashley run up the stairs without books from the very bottom to the very top 4. Record the time of Ashley going up the stairs without books with a stopwatch 5. Give Ashley the four books 6. Have Ashley run up the stairs with the four books from the very bottom to the very top 7. Record the time of Ashley going up the stairs with books with a stopwatch 8. Repeat steps 3-7

• Word count: 999
• Level: International Baccalaureate
• Subject: Physics

#### Refraction of Light by Water

Refraction of Light by Water and Refraction of Water into Air PURPOSE: . To investigate the refraction of light by water 2. To investigate the refraction of water into light 3. To develop Snell's Law MATERIALS: Refer to pp.46-47 of Physics 11 Laboratory Manual. Theory and Hypothesis: When we observe a straw in water, the straw appears to be disjointed because we are used to seeing light in a straight line. According to Snell's Law ( where 1 is the incident ray and 2 is the refracted ray), when light passes from a less dense to a more dense medium, the refracted ray should "bend" away from the normal; and when light is shot back from water into air, the refracted should "bend" toward the normal. This experiment should show us the results of Snell's Law by producing observed angles similar to the calculated angles. If I graph Sin i against Sin R of light from air into water, I should produce a straight line whose slope should resemble the n2 value of Snell's Law because n1 is the index of refraction of air, which is approximately 1. PROCEDURES: Refer to pp.46-47 of Physics 11 Laboratory Manual. DATA AND OBSERVATIONS: Table 1 - Refraction of Light by Water Observation Angle of incident ray (i) (± 1.0°) Angle of Refracted ray (R) (± 1.0°) Sin i Sin R Sin i/Sin R 0.0° 0.0° 0.0 ± 0.0 0.0 ± 0.0 Undefined 2 0.0° 8.0° 0.174 ± 0.034 0.14 ±

• Word count: 1385
• Level: International Baccalaureate
• Subject: Physics

#### Investigating radioactive decay using coins

Challenge 10-Investiaging radioactive decay using coins. Research question: Does our radioactive modeling with coins illustrate radioactive decay? Hypothesis: I believe that it is possible to illustrate radioactive decay by trying to model it using coins. Radioactive decay is a random process and is not affected by external conditions. This means that there is no way of knowing whether or not a nucleus is going to decay within a certain period of time. However, due to the large numbers of atoms involved we can make some accurate predictions. For example, if we start with a given number of atoms then we can expect a certain number to decay in the next minute. If there were more atoms in the sample, we would expect the number decaying to be larger. As a result the rate of decay of a sample is directly proportional to the number of atoms in the sample. This proportionality means that radioactive decay is an exponential process. As a result, I believe that we can model radioactive decay using coins because by chance we should get half of the coins left each time which is exactly what half-life is. Variables: Independent variable: I am not sure about this one because I don't really think there is an independent variable in this investigation because we aren't changing anything other than the number of parent coins every time we throw them. Dependant variable: Similarly,

• Word count: 1268
• Level: International Baccalaureate
• Subject: Physics

#### Pendulum lab. The main purpose for this experiment is to find the factor that will affect the time of a pendulum. In this scenario, the length is the one of the factor that will affect time.

Shin Park Mellin 4B Pendulum Lab Introduction A pendulum is a weight hanging from the pivot. When pulled back from a certain point and releases, the weight swings freely down by the force of gravity and swinging back and forth due to its inertia. The main purpose for this experiment is to find the factor that will affect the time of a pendulum. In this scenario, the length is the one of the factor that will affect time. During the experiment, the length of the string will altered to investigate the time period effect. Variables (X,Y) The independent variable for this investigation will be the length of the string that will affect the dependent variable, which is time (t) that takes to complete ten cycle of swinging left and right. As the length of the strings stretches or condense, it will take effect on time. Controlled variables * Length between the string and the peak of the T-bar, which is 30 centimeters. * The weight of the bob is 1000 grams. * Earth's gravity 9.81 m/ s 2 Materials & Procedures Materials I will use to conduct the pendulum lab are string, bob (1000 grams), T-bar, meter stick, and a stopwatch. One of my classmates will contribute to the experiment using a stopwatch to measure time while I conduct the procedures. . When all the materials are gathered, attach the T-bar to the lab table. 2. Tie the string to the T-bar 30 centimeters away

• Word count: 1015
• Level: International Baccalaureate
• Subject: Physics

#### Motion in a Circular Orbit

Lab no. 6 - Title: Motion in a Circular Orbit Aim: to verify the expression for the centripetal force Equipment: rubber bung, glass tube, string, weights, paper clip, meter ruler, scales Fig. 1: experiment in action. Required Knowledge: Linerization of the graph by deriving from Centripetal Force formula, F=mg, and drawings Derivation: Data Collection and Processing. Collected Data Trial M (kg) Trial A (s) Trial B (s) Trial C (s) Avg. (s) (s) l (cm) (cm) 0.118 0.400 0.484 0.478 0.454 0.4 21.5 1 2 0.178 0.403 0.407 0.403 0.404 0.4 21.5 1 3 0.245 0.369 0.366 0.360 0.365 0.4 21.5 1 4 0.315 0.319 0.344 0.360 0.341 0.4 21.5 1 5 0.380 0.276 0.254 0.280 0.270 0.4 21.5 1 6 0.442 0.280 0.249 0.270 0.266 0.4 21.5 1 Calculated Trial () () 4.85 0.8 2 6,13 0.8 3 7.51 0.8 4 8.60 0.8 5 3.72 0.8 6 4.13 0.8 now, we should use the slope formula to find the slope, and then we should compare slope = but without g, andthen calculate g Conclusion: Even when we take into consideration the uncertainty for the period, having an uncertainty for gravity being over 4 ms^-2 is certainly not correct. Despite having paid utmost attention to the experiment's accuracy by, for example, using 10 loops instead of 1 to find the period, or having 3 trials, and averaging the results, gravity was still not close enough to approximate

• Word count: 570
• Level: International Baccalaureate
• Subject: Physics

#### Physics Wave revision question

. Water waves at the surface of a pond pass a floating log of length L. The log is at rest relative to the bank. The diagram shows wave crests at one instant. The number of crests passing the log per unit time is N. The speed of the water waves relative to the log at rest is A. (N - 1). B. (N - 1). C. (N). D. (N). (1) 2. Two identical triangular pulses of amplitude X travel toward each other along a string. At the instant shown on the diagram below, point M is midway between the two pulses. The amplitude of the disturbance in the string as the pulses move through M is A. 2X. B. X. C. D. 0. (1) 3. A person is walking along one side of a building and a car is driving along another side of the building. The person can hear the car approach but cannot see it. This is explained by the fact that sound waves A. travel more slowly than light waves. B. are diffracted more at the corner of the building than light waves. C. are refracted more at the corner of the building than light waves. D. are longitudinal waves. (1) 4. A pulse is sent down a string fixed at one end. Which one of the following diagrams best represents the reflected pulse? (1) 5. The displacement d of a particle in a wave varies with distance x along a wave and with time t as shown below. Which expression gives the speed of the wave? A. B. C. D. (1) 6. A plane wave approaches and

• Word count: 759
• Level: International Baccalaureate
• Subject: Physics

#### Uncertainties in timing a tennis ball hitting the ground

Matthieu Robin 13/09/08 Physics 1th Grade Uncertainties in timing a tennis ball hitting the ground Introduction In a group of four, the aim was to record the time of a tennis ball being dropped from a certain point on the third floor of the Great Portland Place school campus until it hit the ground of the ground floor; and then record the uncertainties of the experiment. In this experiment the following apparatus was used; * two stopwatches which measures to 2 decimal places (1/100 of a second - centiseconds) * 4 ordinary tennis balls * Utensils to record the time of each tennis ball try There was 21 tries done using 4 different tennis balls, in order to gain sufficient data to provide a measurement of time taken. In order to improve the accuracy of the time of one try, time was recorded from the third floor and the ground floor simultaneously. These measures were all mainly relied upon our auditory and visionary perceptions. The results collected was then be used to calculate the most accurate gauge for a tennis ball being dropped from the third floor of the Great Portland Place campus until it hits the ground, without ignoring the inaccuracies which occurred during the experiment. Raw and Manipulated Data Tennis ball dropping tries Time measured from the ground

• Word count: 1564
• Level: International Baccalaureate
• Subject: Physics

#### Efficiency lab

Title: Efficiency lab Purpose: Find the efficiency of three different spheres Variables: Manipulated Variable: the type of ball used Responding Variable: height of the first bounce of the ball when it is dropped from 2m Controlled Variables: the force applied on the ball, the height at which the ball is dropped, flat surface Hypothesis: the efficiency of a sphere is going to depend largely on its mass and size, the less the mass and size, the higher that it will bounce, because the lesser the mass, the lesser amount of energy will be needed to push it up against the downward pull of gravity, and the smaller the size, the lesser friction air will create when it is bouncing up. This means that the golf ball is possibly going to be the one that bounces the highest and the most efficient, the tennis ball will bounce the second highest and the second most efficient, and the field hockey ball will bounce the third highest and the least efficient. Materials: * * golf ball * tennis ball * field hockey ball * a flat surface * 2 meter sticks * tape * electronic balance Procedures: . Mass each of the spheres using the electronic balance and record the mass 2. Use two meter sticks and tape one end of each together forming a 2m stick 3. Position the two meter sticks perpendicular to the ground and parallel to the wall, station them by taping them onto the wall 4.

• Word count: 668
• Level: International Baccalaureate
• Subject: Physics

#### Temperature of the sun

Temperature of the sun practical - Draft Results: Mass of plastic bag with water: 0.325kg ±0.001 Area of plastic bag: 0.368m² ±0.005 Initial temperature of water: 26°C ±0.5 Time of water left under the sun (s) ±0.5 Temperature of water (°C) ±0.5 300 29 600 31 900 33 200 38 500 42 800 45 Calculation: Errors: Conclusion: The experimental value of the sun's temperature is 1867°C ±80 The literal value of the sun's temperature is 5500°C My experimental value is not in range of the literal value, the results are different as there are uncertain factors. Therefore, the experiment does not seem to be successful and the results obtained are inaccurate. Evaluation: Limitations Suggestions - The plastic bag is not stabilized on the ground; it leads to the spill of water. This will make the result inaccurate as the mass is changing - Use a container which allows the thermometer to be placed in the water at the same time as it is stabilized on the ground - The area of the plastic bag with water is hard to measure as the shape of the bag changes when it is containing water. This will lead to an inaccurate value of area of plastic bag - Use a fixed shape box to contain water which allows the area to be measured accurately - The black water is more concentrated at the bottom which may cause unequal absorption of heat by the water - Use a container

• Word count: 262
• Level: International Baccalaureate
• Subject: Physics

#### Physics laboratory: solving units with two different sets of instruments

Physics laboratory: solving units with two different sets of instruments. Context: The following physics laboratory bases on recording and analyzing data. The principal concern this exercise has, is to measure a microscope slide with distinct varieties of instruments, and from it organize, process, and operate the data in a respective manner (in order for the end, to solve the volume and mass and thus have the desired density). A micrometer (measures to a preciseness of + 0,001cm), a vernier (measures to a preciseness of + 0,01 cm), a common ruler (measures to a preciseness of + 0,1 cm) are the instruments implemented on this work, to demonstrate how small, slight changes of number s, at the end gives up a better or worse answer. E.g. When referring to engineering, a microscopic gap can make the difference between a safe plane flying for many years, and a plane that crashes at a young age. Manipulating so many pieces of data may become confusing, thus a procedure (method) has to take place. Method: The laboratory was divided onto two sections; initially were the instruments of less recording preciseness (Manual measuring balance, and a common ruler; preciseness of + 0,1 cm) and then the detailed instruments. Its Width, length, height were measured and written. From it, its percentage errors and possible errors were solved. The purpose of the percentage error is to

• Word count: 457
• Level: International Baccalaureate
• Subject: Physics