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3.19 practical: investigate the refractive index of glass, using a glass block

1.       Set up your apparatus as shown in the diagram using a rectangular block.

2.       Shine the light ray through the glass block

3.       Use crosses to mark the path of the ray.

4.       Join up crosses with a ruler

5.       Draw on a normal where the ray enters the glass block

6.       Measure the angle of incidence and the angle of refraction and add these to your results table

7.       Calculate the refractive
index

8.       Repeat steps 2 – 7 using
a different angle of
incidence

9.       Find an average of your
results.

 
2019-06-28T09:16:03+00:00Categories: (d) Light and sound, 3 Waves, Edexcel iGCSE Physics, Uncategorized|Tags: , , , , , , |

3.21 explain the meaning of critical angle c

Critical Angle:

  • The angle of incidence which produces an angle of refraction of 900 (refracted ray is along the boundary of the surface).
  • When the angle of incidence is greater than the critical angle, total internal reflection occurs (all light is reflected at the boundary).
  • This effect only occurs at a boundary from a high refractive index material to a low refractive index material.
2022-11-29T15:01:06+00:00Categories: (d) Light and sound, 3 Waves, Edexcel iGCSE Physics, Uncategorized|Tags: , , , , , , , |

3.26 understand how an oscilloscope and microphone can be used to display a sound wave

With the microphone plugged into the oscilloscope and a sound incident on the microphone, the microphone will transfer the sound into an electrical signal which the oscilloscope can display .The x axis show the time base which can be adjusted for example 2ms for 1 square so time period and frequency can be calculated from this, along the y axis voltage is displayed as the wave is converted into an electrical signal this means amplitudes can be compared.
2019-06-27T08:14:34+00:00Categories: (d) Light and sound, 3 Waves, Edexcel iGCSE Physics, Uncategorized|Tags: , , , |

4.01 use the following units: kilogram (kg), joule (J), metre (m), metre/second (m/s), metre/second2 (m/s2), newton (N), second (s) and watt (W)

know the units for 

Mass = kilogram (kg)

energy = joule (J)

velocity = metre/second (m/s)

acelleration = metre/ second 2 (m/s2)

force = newton (N)

time = second (s)

power = watt (W) 

 

2022-11-29T15:03:24+00:00Categories: 4 Energy resources and energy transfers, 4(a) Units, Edexcel iGCSE Physics, Uncategorized|Tags: , , , , , , |

4.02 describe energy transfers involving energy stores: energy stores: chemical, kinetic, gravitational, elastic, thermal, magnetic, electrostatic, nuclear and energy transfers: mechanically, electrically, by heating, by radiation (light and sound)

Energy Stores:

Chemical – e.g. the food we eat

Kinetic – movement energy

Gravitational – objects that are lifted up

Elastic – e.g. from springs

Thermal – from hot objects

Magnetic – objects in magnetic fields

Electrostatic – charged objects

Nuclear –  stored within a nucleus

 

 
2022-11-29T15:03:36+00:00Categories: (b) Energy transfers, 4 Energy resources and energy transfers, Edexcel iGCSE Physics, Uncategorized|Tags: , , , , , , |

4.05 describe a variety of everyday and scientific devices and situations, explaining the transfer of the input energy in terms of the above relationship, including their representation by Sankey diagrams

The energy flow is shown by arrows whose width is proportional to the amount of energy involved. The wasted and useful energy outputs are shown by different arrows.

 

2022-11-29T15:04:19+00:00Categories: (b) Energy transfers, 4 Energy resources and energy transfers, Edexcel iGCSE Physics, Uncategorized|Tags: , , , , , , |

4.06 describe how thermal energy transfer may take place by conduction, convection and radiation

Conduction is the transfer of thermal energy through a substance by the vibration of the atoms within the substance. Metals are good conductors because they have free electrons that can move easily through the metal, making the transfer of energy happen faster.

 

Convection occurs in a liquid or gas. These expand when heated because the particles move faster and take up more volume – the particles remain the same size but become further apart. The hot liquid or gas is less dense, so it rises into colder areas. The denser, colder liquid or gas falls into the warm areas. In this way, convection currents are set up which transfer heat from place to place.

 

Thermal radiation is the transfer of energy by infrared (IR) waves. These travel very quickly in straight lines.

2019-06-27T08:19:42+00:00Categories: (b) Energy transfers, 4 Energy resources and energy transfers, Edexcel iGCSE Physics, Uncategorized|Tags: , , , |

4.08 explain how emission and absorption of radiation are related to surface and temperature

–          Light, shiny surfaces are good reflectors of IR and so are poor at absorbing it.

–          Dark, matt surfaces are poor reflectors and good at absorbing IR.

–          This means that placed next to a heat source, a dark object would heat up faster than a light one.

–          Dark matt surfaces are also best at emitting IR. This means that a hot object with a light shiny surface will emit less IR than a dark matt object at the same temperature.

–          Hotter objects emit more IR per second. The type of EM wave emitted also changes with temperature – the higher the temperature the higher the frequency of EM wave emitted.
2019-06-27T08:20:29+00:00Categories: (b) Energy transfers, 4 Energy resources and energy transfers, Edexcel iGCSE Physics, Uncategorized|Tags: , , , |

4.10 explain ways of reducing unwanted energy transfer, such as insulation

A good insulating material is a poor conductor that contains trapped air, e.g. foam, feathers, glass fibre. Being a poor conductor (non-metal) prevents heat transfer by conduction and the trapped air prevents convection currents.

2019-06-27T08:21:27+00:00Categories: (b) Energy transfers, 4 Energy resources and energy transfers, Edexcel iGCSE Physics, Uncategorized|Tags: , , , |

4.13 know and use the relationship between gravitational potential energy, mass, gravitational field strength and height: GPE = m × g × h

Gravitational potential energy  (J) =  Mass (kg) x gravitational field strength (N/kg) x height (m) 

2022-11-29T15:12:52+00:00Categories: (c) Work and power, 4 Energy resources and energy transfers, Edexcel iGCSE Physics, Uncategorized|Tags: , , , , , , |

4.15 understand how conservation of energy produces a link between gravitational potential energy, kinetic energy and work

Because energy is conserved the decrease in GPE = increase in KE, for a falling object if no energy is lost to the surroundings

2022-11-29T15:13:21+00:00Categories: (c) Work and power, 4 Energy resources and energy transfers, Edexcel iGCSE Physics, Uncategorized|Tags: , , , , , , |

5.01 use the following units: degree Celsius (°C), Kelvin (K), joule (J), kilogram (kg), kilogram/metre3 (kg/m3), metre (m), metre2 (m2), metre3 (m3), metre/second (m/s), metre/second2 (m/s2), newton (N) and pascal (Pa)

The units for:

temperature: degree Celsius (°C) or Kelvin (K)

Energy: Joule (J)

mass: Kilogram (kg)

density: kilogram/metre cubed (kg/m3)

distance: metre (m)

area: metre squared (m2)

volume: metre cubed (m3)

velocity: metre per second (m/s)

acceleration: metre per second squared (m/s2)

force: newton (N)

pressure: pascal (Pa)

2022-11-29T15:14:23+00:00Categories: 5 Solids, liquids and gasses, 5(a) Units, Edexcel iGCSE Physics, Uncategorized|Tags: , , , , , , , , |

5.04 practical: investigate density using direct measurements of mass and volume

  • The density of an object can be found by measuring the mass and volume and applying the formula above to calculate the density.
  • For a regular object use a ruler to measure the lengths needed to determine the volume.
  • For an irregular object submerge it in water and measure the displaced volume.
  • Measure the mass of either type of object using a measuring balance.
2019-06-27T11:20:00+00:00Categories: (b) Density and pressure, 5 Solids, liquids and gasses, Edexcel iGCSE Physics, Uncategorized|Tags: , , , , , |

5.07 know and use the relationship for pressure difference: p = h × ρ × g

Pressure difference [Pa] = Density [kg/m3] x g [N/kg] x Height [m]

ΔP = ρ g h

  • The equation can be used in liquids or gases provided you know their densities.

P1 – Patm = ρ g h

P1 = ρ g h + Patm

2019-06-27T11:21:33+00:00Categories: (b) Density and pressure, 5 Solids, liquids and gasses, Edexcel iGCSE Physics, Uncategorized|Tags: , , , , , |

5.10 describe the arrangement and motion of particles in solids, liquids and gases

solids:

  • Tightly packed
  • Held in fixed pattern
  • Vibrate about fixed positions

liquids:

  • Tightly packed
  • Can slide over each other

gasses: 

  • Very spread out
  • Move with rapid, random motion

 

2019-06-28T09:23:48+00:00Categories: (c) Change of state, 5 Solids, liquids and gasses, Edexcel iGCSE Physics, Uncategorized|Tags: , , , , , , |

5.11 practical: obtain a temperature–time graph to show the constant temperature during a change of state

  1. Remove the boiling tube of stearic acid from
    the water bath
  2. Place the tube into a beaker of room
    temperature water
  3. Add a separate thermometer to the water
  4. Take readings from the thermometer in the
    stearic acid and the water every minute
    [Make sure to avoid parallax error while doing so]
  5. Note readings in the table below
  6. Note on the table when you observe the stearic
    acid change from a liquid to a solid.
  7. Plot your results in a graph
2019-06-28T09:24:26+00:00Categories: (c) Change of state, 5 Solids, liquids and gasses, Edexcel iGCSE Physics, Uncategorized|Tags: , , , , , |

5.12 know that specific heat capacity is the energy required to change the temperature of an object by one degree Celsius per kilogram of mass (J/kg °C)

Specific heat capacity:

  • Amount of heat energy required to increase the temperature of 1kg of a substance by 10
  • Unit J/kg 0C
2019-06-28T09:25:06+00:00Categories: (c) Change of state, 5 Solids, liquids and gasses, Edexcel iGCSE Physics, Uncategorized|Tags: , , , , , |

5.14 practical: investigate the specific heat capacity of materials including water and some solids

  1. Set up the apparatus as shown the diagram.
  2. Make note of all measurements: current (A), potential difference (V), mass (kg).
  3. Use the electronic balance to measure the mass of your
  4. Record the initial temperature of you block.
  5. Switch on the heater and start your stopwatch.
    [You will now leave the heater on for 10 minutes]
  6. While the heater is switched on take readings from the
    Ammeter and the Voltmeter.
  7. Use these to calculate the Thermal Energy that will be
    supplied to the block in 10 minutes
  8. Record the temperature of your block after 10 minutes.
  9. Calculate the Change in Temperature
2019-06-28T09:26:27+00:00Categories: (c) Change of state, 5 Solids, liquids and gasses, Edexcel iGCSE Physics, Uncategorized|Tags: , , , , , |

5.15 explain how molecules in a gas have random motion and that they exert a force and hence a pressure on the walls of a container

Gas laws:

  • Gas molecules have rapid and random motion.
  • When they hit the walls of the container, they exert a force.
  • Pressure = Force/Area
2022-11-29T15:15:53+00:00Categories: (d) Ideal gas molecules, 5 Solids, liquids and gasses, Edexcel iGCSE Physics, Uncategorized|Tags: , , , , , , |

5.20 Explain, for a fixed amount of gas, the qualitative relationship between: pressure and volume at constant temperature, pressure and Kelvin temperature at constant volume.

  • As you heat the gas, the kinetic energy of the particles increases, and thus so does their average speed.
  • This means more collisions per second with the walls, and they exert a larger force on the wall.
  • This causes in the total pressure being exerted by the particles to rise.
  • If temperature is constant, the average speed of the particles is constant.
  • If the same number of particles is placed in a container of smaller volume they will hit the walls of the container more often.
  • More collisions per second means that the particles are exerting a larger force on the wall over the same time, so average force exerted on the walls has increased.
2022-11-29T15:17:53+00:00Categories: (d) Ideal gas molecules, 5 Solids, liquids and gasses, Edexcel iGCSE Physics, Uncategorized|Tags: , , , , , , |
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Section 1: Principles of chemistry

      a) States of matter

      b) Atoms

      c) Atomic structure

     d) Relative formula masses and molar volumes of gases

     e) Chemical formulae and chemical equations

     f) Ionic compounds

     g) Covalent substances

     h) Metallic crystals

     i) Electrolysis

 Section 2: Chemistry of the elements

     a) The Periodic Table

     b) Group 1 elements: lithium, sodium and potassium

     c) Group 7 elements: chlorine, bromine and iodine

     d) Oxygen and oxides

     e) Hydrogen and water

     f) Reactivity series

     g) Tests for ions and gases

Section 3: Organic chemistry

     a) Introduction

     b) Alkanes

     c) Alkenes

     d) Ethanol

Section 4: Physical chemistry

     a) Acids, alkalis and salts

     b) Energetics

     c) Rates of reaction

     d) Equilibria

Section 5: Chemistry in industry

     a) Extraction and uses of metals

     b) Crude oil

     c) Synthetic polymers

     d) The industrial manufacture of chemicals

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