Required Practicles

• Specific heat capacity-method


  1. Measure the mass of the block .

  2. Wrap it in an insulating layer.

  3. Measure the initial temperature of the block . Then turn on the power

  4. Take readings of the temperature and power every minute for 10 minutes .

  
• Specific heat capacity - variables

  Independant: Energy transferred

  Dependant: Temperature change

  Control: Insulator, time
• Specific heat capacity - sources of error

  -Unwanted energy transfer

  -Incorrect thermometer reading

  -Ineffective insulation
• Specific heat capacity - formula

  Thermal energy (J) = mass (g) x shc (c) x temperature change (θ°c)
• Factors Affecting Resistance - method

  1. Attach a crocodile clip to the wire at 0cm on the ruler

  2. Attach a second crocodile clip to the wire 10 cm away from the first clip

  3. Record the current and pd flowing through it

  4. Move the second crocodile clip another 10cm along the ruler

  5. Repeat this for a number of lengths whilst recording current and pd

  6. Calculate resistance

  
• Factors affecting resistance - variables

  Independent - Length of wire

  Dependant - Resistance

  Control - Material of wire, components
• Factors affecting resistance - notes

  -Crocodile clips causes resistance

  -High current increases temperatures, which increases resistance
• Factors affecting resistance - formula


  Voltage (V) = current (A) x resistance (Ω)
• IV characteristics - method

  1. Set up the circuit as shown

  2. Take readings for the current and voltage

  3. Vary the resistance and take more readings

  4. Swap over the wires connected to the cell , so the direction of the current is reversed.

  5. Plot graph for current against voltage for each component

  
• IV characteristics - variables


  Independent - Component, direction of battery

  Dependant - Current, voltage

  Control - temperature
• IV characteristics - formula


  Voltage (V) =current (A) x resistance (Ω)
• Density - method (liquid)

  1. Measure the mass of an empty cylinder

  2. Add the liquid and record the mass

  3. Record the volume of liquid

  4. Find the mass of liquid and calculate density
• Density - method (regular object)

  1. Measure the mass of the object

  2. Multiply the length, width and height to find the volume

  3. Calculate density

  
• Density - method (irregular object)

  1. Measure the mass of the object

  2. Fill a eureka can with water and put a beaker under the spout

  3.Completely submerge the object in the can

  4. Measure the volume of water that was displaced

  5. Calculate density

  
• Density - formulae


  Density (g/cm³) =mass (g) ÷ volume (cm³)

  Volume of a cuboid (cm³) = length x width x height
• Density - sources of error


  -Make sure the beaker doesn't overflow

  -Use the same ruler for each measurement
• Thermal insulation - method

  1. Set up some beakers and wrap each one with a different insulator

  2. Pour hot water into the beakers and start a timer

  3. Every few minutes measure the temperature

  4. Plot a graph of the temperature change

  
• Thermal insulation - variables

  Independent - Type of insulator

  Dependant - Temperature decrease

  Control - Mass of water
• Thermal insulation - notes


  -Make sure the thermometer is in the water

  -Use the same volume of water
• Force and extension - method

  1. Set up the equipment as shown

  2. Record the length of the spring with no force attached

  3. Hang a 1N weight on the end of the spring

  4. Record the new length of the spring

  5. Continue adding more weight and recording it until you have enough results

  6. Subtract the unstretched length from each reading, this is the extension

  7. Plot a graph of extension and weight on a graph

  
• Force and extension - results

  - The graph will be directly proportional

  - The limit of proportionality is the maximum weight that can be applied to a spring without deforming it
• Force and extension - notes

  - The top of the spring must start at the zero point on the metre rule

  - The metre rule must be vertical

  - The pointer must be horizontal
• Force and extension - formula


  Spring constant (Nm) = Force (N) x extension (m)
• Acceleration - method


  1. Attach a toy car to a piece of string, which goes through a pulley over the end of the table. Measure the length of the table. Attach a 1N weight to the spring

  2. Let go of the car and allow it to travel the full length of the table while recording the time

  3. Repeat with different weights

  
• Acceleration - notes


  - The overall mass of the system shouldn't change

  - The experiment can be done with different mass, rather than different weight, for that experiment attach a mass to the car
• Acceleration - variables


  Independant - Weight

  Dependant - acceleration

  Control - Distance, mass of car
• Acceleration - formula


  Force (N) = mass (g) x acceleration (m/s²)
• Ripple Tank: wavelength - method

  1. Using a signal generator attached to the dipper of a ripple tank, you can create waves at a certain frequency.

  2. Use a strobe light to see wave crests on the screen

  3. Measure the length of 10 waves

  4. Divide this by 10 to find the wavelength of 1 wave

  
• Ripple tank: frequency - method

  1. Record how many waves pass a certain point in 10 seconds

  2. Divide the no. of wave by 10 to find the frequency

  
• Ripple tank-formula


  Wave speed (m/s) = frequency (Hz) x wavelength(m)
• Waves in a solid - method

  1. The vibration generator is attached to a signal generator which hallows us to change the frequency

  2. When the vibration generator is turned on a standing wave will form

  3. Measure the wavelength of this wave

  4. Divide this by the number of half waves the multiply by 2

  5. Calculate the wave speed

  6. Repeat at multiple frequencies

  
• Waves in a solid - variables

  Independant - frequency

  Dependant - wave length

  Control-Distance, mass, components
• Waves in a solid - formula

  Wave length = 2(Whole length ÷ no. of half waves)
• Reflection and refraction - method

  1. Set up a ray box with a lens and a card with a slitting it to produce a narrow beam of light

  2. Use a ruler to draw a line in the centre a piece of a paper

  3. Draw another line at 90° to the first line and label this the normal

  4. Place a glass block against the first line so the normal is in the middle. Sketch around the block

  5. Shine a ray of light so it hits the block at the normal

  6. Mark the path of the incidence, reflected and transmitted rays and remove the glass block

  7. Draw a line in the bock outline between the incidence and transmitted lines

  8. Measure the angles of incidence, reflection and rarefaction

  9. Repeat with different materials
• Refraction


  The slowing down or speeding up of waves to produce different angles

  
• Reflection


  When incoming waves hits an object and bounces off it at the same angle

  
• Reflection and refraction-notes


  - Ray boxes get hot so it's important to turn them off when not in use

  - All the lights in the room should be off
• Infrared: emission - method

  1. Fill a Leslie's cube wit hot water

  2. Point an infrared detector at each face and record the radiation emitted

  
• Infrared - notes


  -The distance between the cube and the detectors must be the same

  -Instead of infrared detectors you can use thermometers with the bulb painted black

  -The matt black surface emits and absorbs the most radiation
• Infrared: emission - variables


  Independant - surface

  Dependant - Amount of emitted infrared

  Control - Distance, equipment