physics practicals paper 1

specific latent heat of fusion

• measure current and voltage using an ammeter and voltmeter respectively

• measure time using a stopwatch

• measure mass of ice melted using a top pan balance

• use control beaker to determine how much ice has melted due to room temperature

• mass melted due to experiment = mass collected from beaker after heating - mass collected from control beaker

• ensure mass starts at 0°C, use a top pan balance with a high resolution to reduce uncertainty

• use heatproof mat and wear gloves when handling the heater

• E = mL, VIt = mL, plot E against m, will give a straight line graph with gradient L

specific latent heat of vaporisation

• take the condenser and measure the mass of liquid that changes phase

• measure the current and voltage using an ammeter and voltmeter respectively

• turn the heater on and time, using a stopwatch, the time it takes for all the liquid to boil

• check thermometer regularly to ensure that the temperature remains at boiling point

• E = mL (m = mass collected from condenser in conical flask), VIt = mL

boyle’s law

• pV = constant

• take sealed tube of pressurised gas with a volume scale

• measure pressure using a pressure gauge

• increase pressure by pumping air into the tube and record the new pressure and volume readings

• take repeat readings and find an average volume for each pressure in order to reduce percentage uncertainty

• gradually increase pressure to ensure that the temperature remains constant, ensuring not to pass the safe pressure limit of the equipment

• plot a graph of p against 1/V, straight line graph through the origin to prove relationship

pressure law

• p/T = constant

• immerse flask in water bath

• increase temperature using a heater or bunsen burner

• measure pressure using pressure gauge and temperature using a thermometer, ensuring to take multiple readings and average to reduce percentage uncertainty

• plot a graph of p against θ, straight line graph, extrapolate to find the x intercept (when pressure = 0)

• at absolute 0, internal energy is at a minimum

circular motion (whirling bung)

• measure mass using top pan balance

• measure time using a stopwatch

• measure 10 time periods then divide by 10 to find T, reducing percentage uncertainty

• measure radius r using a ruler, taking multiple readings and averaging to reduce random errors

• ensure that the radius remains constant throughout by marking radius with a pen and ensuring that it is at the edge of the cylinder for each rotation

• vary the mass m and calculate the speed v for each mass value using the equation v = 2πr/T, find v²

• plot a graph of f against v², straight line graph through the origin