length of a simple pendulum affects the time
. Plan Aim To investigate how the length of a simple pendulum affects the time for a complete swing. Variables length The length of the pendulum has a large effect on the time for a complete swing. As the pendulum gets longer the time increases. size of swing Surprisingly, the size of the swing does not have much effect on the time per swing. mass The mass of the pendulum also does not affect the time. air resistance With a small pendulum bob there is very little air resistance. This can easily be seen because it takes a long time for the pendulum to stop swinging, so only a small amount of energy is lost on each swing. A large and light pendulum bob would be affected by a significant amount of air resistance. This might change the way the pendulum moves. gravity The pendulum is moved by the force of gravity pulling on it. On the Moon, where the pull of gravity is less, I would expect the time for each swing to be longer. Theory When the pendulum is at the top of its swing it is momentarily stationary. It has zero kinetic energy and maximum gravitational potential energy. As the pendulum falls the potential energy is transferred to kinetic energy. The speed increases as the pendulum falls and reaches a maximum at the bottom of the swing. Here the speed and kinetic energy are a maximum, and the potential energy is a minimum. As the pendulum rises the
The purpose of this experiment is to see what factors affect the period of one complete oscillation of a simple pendulum.
SCIENCE COURSEWORK PENDULUM EXPERIMENT Aim The purpose of this experiment is to see what factors affect the period of one complete oscillation of a simple pendulum. In this investigation I am going to discover and investigate the factors, which affect the time for one complete oscillation of a simple pendulum. It is important to understand what a pendulum is. A pendulum has a weight or mass fixed and left hanging of the string. An oscillation is one cycle of the pendulums motion e.g. from position a to b and back to a. I will time how long it takes for one oscillation of the pendulum. I am going to do a simple preliminary experiment to investigate which of the factors I test have an effect on the time for one complete oscillation. The factors basic variable factors I can test are: ? Length (the distance between the point of suspension and the mass) ? Mass (the weight in g of the item suspended from the fixed point) ? Swing size (the length I release the pendulum) *The point of equilibrium is the point at which kinetic energy (KE) is the only force making the mass move and not gravitational potential energy (GPE). I will test the extremes of these factors as I can assume that if they have any effect on the period of oscillation it will become obvious. To make sure my results are accurate enough to allow for any anomalies I will repeat the experiment 2 times for each
Ionization energies
INTRODUCTION: The ionization energy of an atom measures how strongly an atom holds its electrons.The ionization energy is the minimum energy required to remove an electron from the ground state of the remote gaseous atom The first ionization energy, I1, is the energy needed to remove the first electron from the atom: i.e. the most loosely held electron! Na(g) -> Na+(g) + 1e- The second ionization energy, I2, is the energy needed to remove the next (i.e. the second) electron from the atom Na+(g) -> Na2+(g) + 1e- The higher the value of the ionization energy, the more difficult it is to remove the electron As electrons are removed, the positive charge from the nucleus remains unchanged, however, there is less repulsion between the remaining electrons INVESTIGATION: Periodic trends in ionization energies First ionization energies as a function of atomic number * 1.Within each period (row) the ionization energy typically increases with atomic number * 2.Within each group (column) the ionization energy typically decreases with increasing atomic number HYPOTHESIS: * Investigation 1: As the effective charge increases, or as the distance of the electron from the nucleus decreases, the greater the attraction between the nucleus and the electron. The effective charge increases across a period, in addition, the atomic radius decreases * Investigation 2: As we move
Determine the penetrating power and the range in air of the three radioactive emissions (Plutonium 239 for alpha, Strontium 90 for beta and Cobalt 60 for gamma).
Aim To determine the penetrating power and the range in air of the three radioactive emissions (Plutonium 239 for alpha, Strontium 90 for beta and Cobalt 60 for gamma). Method 1 The apparatus were set up as in the diagram below to measure the range in air up to 50 cm for each source. Before the experiment took place the background radiation was measured as 80 counts in 5 minutes therefore 16 counts per minute. Experimental precautions were: The radioactive source is aligned with a ruler to the GM tube as accurately as possible so that the maximum radiation is measured A set square was used to measure the exact point at which the source and tube were placed The counter was reset each time so the counter read zero so this would reduce zero error in the experiment and the hold button was pressed to freeze the measurement Thirty seconds were left between the start of the count and the recording so the reading would be less instantaneous and more reliable Everything was kept constant for all three experiments and the counts were recorded at regular intervals of 5 cm. Safety precautions included removing the sources from a secure wooden box using thongs and tweezers and placed in plasticene, the set square was held using thongs and all those carrying out the experiment stood behind the source to minimise any direct radiation exposure. Method 2 The equipment was set up
An investigation into the effect of temperature on a squash ball
An investigation into the effect of temperature on a squash ball For my experiment I will be using a blue spotted squash ball. This is because the blue spotted ones are designed to have the most bounciness. This is will make it a lot easier to judge the height of the ball's bounce making my experiment more accurate. I'll set up my equipment to the diagram below. Then I'll put the squash ball in a beaker and then put the beaker in a water bath. The water will obviously be heated with a Bunsen burner which will then heat the ball up. I've chosen this method so the ball doesn't get wet, and the experiment is fair. I will then drop the ball from a height of 2 meters. It will be landing onto a piece of MDF (Medium Density Fibreboard) to make sure the surface won't affect my results, so it's more of a fair test. To judge how high the ball has bounced, I will be using my eyesight. Diagram Equipment list 4 different coloured squash balls Beaker Water bath 2, 1 meter rulers MDF Kettle Ice Thermometer Stopwatch Tongs I did a preliminary experiment to see if my method would work and if there were any problems with the way I will conduct my experiment. Preliminary Results Temperature (ºC) Distanced Bounced (Cm) 90 81 40 68 0 20 Factors affecting my experiment * If I use different squash balls of different elasticity it will affect the bounciness of the
Thermal insulators.
Zeadon Jamil Thermal insulators Aim To investigate different materials for the most effective thermal insulator for a house. Introduction Heat transfer is the gain and loss of energy. There are three ways in which thermal energy can be transferred: * Conduction * Convection * Radiation Conduction - this is when energy travels from molecule to another. When one molecule receives energy it begins to vibrate and hits other molecules and makes them vibrate. And will spread throughout the object. Convection - this will only occur in gases and liquids. When heat is applied to the bottom of the substance, it will heat it up. When it heats up, it will rise to the top, forcing colder areas towards the heat source and then they will receive energy and rise to the top, etc. Radiation - it travels in waves. When it hits a molecule it makes it vibrate. I will be concentrating on conduction, as this is the main way in which thermal energy is transferred lost from housing. Which means that I need something that is a bad thermal conductor (good thermal insulator) to keep the amount of conduction to a bare minimum? Plan I am planning to test five materials (paper, cling film, cloth, bubble wrap and plastic) and one control, three times and find the average (to ensure accuracy). Whichever material changes the temp of the water the least is the best insulator. I will wrap
The factors affecting the resistance of a metalic conductor.
INVESTIGATION: THE FACTORS AFFECTING THE RESISTANCE OF A METALLIC CONDUCTOR Metals conduct electricity because the electrons in the metal can move about inside the structure. These electrons are called free electrons. Electricity is conducted through a conductor by means of free electrons. Atoms consist of protons, electrons and neutrons. The protons and neutrons make the nucleus of an atom while the electrons circle the outer area of the atom. Electrons in metal are able to move freely and are used as current in an electric circuit. This is because they carry a charge and can move all around the circuit with this charge. While these electrons are travelling around the circuit, atoms are sometimes in the way, causing the two to collide. This takes out some of the energy from the electron and transfers it to the atom. This is how resistance occurs. The number of free electrons depends on the material and the more the free electrons in a substance the better the material as a conductor. All conductors offer resistance to the flow of current. The conductor's atoms determine this resistance. For example copper atoms offer negligible resistance to an electric current because a significant proportion of its electrons are free to move from electron to electron. Thus copper is commonly used as a conductor. Current, is the flow of electrons around a circuit. Those materials,
Resistivity Coursework
Resistivity Coursework Theory suggests that the resistance of a wire is found with this formula: R=?L/A R = Resistance ? = Resistivity of wire L = length of wire A = cross-sectional area I will now perform an investigation to confirm the legitimacy of this formula and confirm a value for ? in a Nichrome wire. Planning A4c: Fully labelled Diagram A4d, A6d: Comprehensive list of Apparatus including Instrument Ranges Variable power supply unit Analogue ammeter, accuracy 0.01A, range 0 to 1.0A Analogue Voltmeter, accuracy 0.1V, range 0 to 5V Copper leads x5 Crocodile clip x2 Nichrome Wire (diameter=4.57 x 10-4m) Ruler, accuracy 0.001m, range 0 to 1.000m A2c: Safety Confirm the Initial power supply is at 0 volts other wise huge voltages will most likely cause unnecessary heating in wires including the Nichrome not only a hazard but may compromise my readings. Make sure my practical investigation is free of all or any obstructions; any unnecessary wires may cause a short circuit leading to damaging the power supply unit, ammeters and voltmeters. A4b, A6a: Identifying Variables and Constants The variables in this investigation are voltage (V), resistance (R) and length of Nichrome wire (L). Resistance and length are directly proportional to each other. Constants are current (I), cross sectional area of wire (A) Resistivity (?) and temperature of the Nichrome
Ohm's Law coursework
GCSE Physics- Ohm's Law coursework Aim: I have chosen to investigate how the resistance of a wire is affected by the length of the wire. What is resistance? Electricity is conducted through a conductor, in this case wire, by means of free electrons. The number of free electrons depends on the material and more free electrons means a better conductor, i.e. it has less resistance. For example, gold has more free electrons than iron and, as a result, it is a better conductor. The free electrons are given energy and as a result move and collide with neighboring free electrons. This happens across the length of the wire and thus electricity is conducted. Resistance is the result of energy loss as heat. It involves collisions between the free electrons and the fixed particles of the metal, other free electrons and impurities. These collisions convert some of the energy that the free electrons are carrying into heat. How is it measured? The resistance of a length of wire is calculated by measuring the current present in the circuit (in series) and the voltage across the wire (in parallel). These measurements are then applied to this formula: V = I ´ R where V = Voltage, I = Current and R = Resistance This can be rearranged to: R = V I Ohm's Law It is also relevant to know of Ohm's Law, which states that the current through a metallic conductor (e.g.
What is the best way to keep hot water hot for the longest period of time
Introduction In this practical experiment, I am going to find out what is the best way to keep hot water hot for the longest period of time. The way that this can be achieved is by preventing, Radiation, Convection and Conduction. Planning I am going to apply my background knowledge to the experiment so that it is easier to choose which items I am going to use in the experiment. Here is my background knowledge. Background knowledge I already know that heat can be lost by conduction, convection and radiation. Therefore it would be in great interest to look into these in depth as then I can see how I can prevent these from occurring. The first way I am going to cover is conduction Conduction- Conduction is what occurs in many solids. The way it is mainly passed is through the solids' vibrations. This is how the solid will look as the vibrations are passed through it. Most non-metals are not good conductors and are good insulators as they do not vibrate as much so therefore the process of conduction is very slow. Convection- The convection of heat occurs in liquids and heat only. It is a much more effective process then conduction so I am going to concentrate on stopping convection more then stopping conduction. Convection is when heat from a hot region takes the heat and moves to a cooler region. Here is a picture of what happens in the convection
