9702 A2 Physics Paper 5 Guide Lee Suit Lin/MCKL/ 2020/ suitlin@gmail.com/ 012-6679171 QUESTION 1 1) Analyse the situation presented, pay attention to the equation. 6) Analysis [A3] • Straight lines only. 2) Tabulate the variables/constants in a table to not miss out crucial points in your explanation Variables Independent (Varied) Dependent (Measured) Constant (Unchanged) • Avoid log or ln graphs unless given an equation with exponents • Use y=mx+c to determine an expression for the desired constant in the experiment. Physical Quantity • EXPRESS this constant as the subject of your equation Measurements: include tools and set-up Extra details, eg: • Discuss the relationship validity from the suggested graph. • • • Equations if direct measurements are impossible. Repeat measurement Calibrate instrument 3) Define the problem [P2] 4) Diagram [M1 or M2, D1] • Can copy diagram if given. • All items needed to measure variables in table above are clearly labeled. • Circuit diagram drawn if relevant • Clamp, secure all objects that need support on the bench 5) Method– make use of the table. Write in point form. [M2 or 3, few D points] • How will you vary the independent variable? • How will you measure the dependent and independent variables? • Repeat measurements a) shape is circle/ irregular – different position AND average 7) Extra details • shocks, burns from hot objects etc. [D1] b) for the (independent variable) to obtain more values of (dependent variable) AND average • Be specific. Safety/Precaution – damage to skin/eyes, high voltage electric • Prep/Set-up of experiment – plumbline, set square, etc etc, any forgotten points can be written here. 9702 A2 Physics Paper 5 Guide Physical Quantity Lee Suit Lin/MCKL/ 2020/ suitlin@gmail.com/ 012-6679171 Instrument /Measurement Past Year Examples Additional Detail Directly measurable quantities – some examples, not all inclusive. 1 2 Height – Vertical height Length of strings, spring, Metre rule Metre rule stretch/moving things. MJ19P51 • clamp rule + ensure vertical using plumb line or set-square. ON19P51 & 52 • Clearly state distance and equation of relevant MJ20P51 • repeat measurements and average. MJ20P53 • Use a marker. • If movement involved while measuring, clamp rule, view video playback frame by frame 3 4 5 Diameter/Thickness Vernier caliper/ micrometer Mass Balance Time / period. Stop watch /light gate MJ20P52 MJ14P51 • Use safety googles to prevent injury (to eyes) from moving spring/load • Use cushion/sand box in case load falls. • repeat at different position and average • Radius cannot be measured, use r=d/2 • view video playback frame by frame • Clearly indicate start and stop of timing • Indicate position of light gate • For oscillation, take 5, 10, or 20 complete cycles. Current/ Voltage/ Power/ Ammeter ON13P53 • Draw Circuit Diagram Heat energy/Resistance Voltmeter ON15P53 • Include equation MJ17P52 ON17P51 FM19P52 • 6 Temperature Thermometer 7 Pressure Manometer/pressure gauge ON18P51 & 52 & 53 • sealed bell jar/conical flask 8 Force Newton meter or weighing FM18P53 • Example of top pan balance balance (Vertical force) MJ18P51 9702 A2 Physics Paper 5 Guide 9 10 Angle Lee Suit Lin/MCKL/ 2020/ suitlin@gmail.com/ 012-6679171 Protractor/ruler ON15P51 • use relevant trigo identity MJ19P52 • Use plumb line for alignment if needed • Cannot be measured directly • state equation used to calculate volume/area Water displacement method for irregularly shaped objects. Volume or surface area Metre rule to measure of regular shapes appropriate lengths 11 Volume (Liquid) Measuring Cylinder • 12 Volume (Gas) Measuring Cylinder • 13 Density Measure mass and volume • State density equation 14 Average Velocity/ Measure time and MJ16P52 • Use relevant equation of motion. acceleration displacement of object FM17P52 MJ17P51 15 16 Wavelength of light Frequency / Intensity of Determined using Young MJ18P52, • Use filter / different LED double slit or diffraction MJ16P51, • Include relevant equation grating. ON12P53 Read on CRO MJ15P52 • Use signal generator to vary • Include Mic and loudspeaker sound wave 17 Magnetic Flux Density Hall Probe MJ14P52 • to vary, change current in coils [ON12P52, ON14P53 • to measure, calibrate hall probe with a known field ON16P51 • to set-up, rotate hall probe until max reading on voltmeter. • to vary, use signal generator, use small frequency. ON16P52 ON17P52 FM20P52 18 Alternating Current Frequency/peak values Read on CRO MJ13P52 ON13P51 MJ15P51 9702 A2 Physics Paper 5 Guide Lee Suit Lin/MCKL/ 2020/ suitlin@gmail.com/ 012-6679171 Question 2 1) Follow the question. Y=mX+C 2) Common uncertainty identities 5) Gradient & Uncertainty • Clear triangle – dotted line • Coordinates taken and shown substitution 3) Plot & Error bars [SHARP PENCIL] • Plot at corners, no larger than size of one small box. • Bars – symmetrical, CLEARLY drawn – can be EITHER horizontal OR vertical. 6) Y-intercept & uncertainty • 4) Best Fit and Worse Fit [SHARP PENCIL] • Label lines. BF should be close to all points with balanced points above and below line. • WF with steepest or shallowest slope – should pass all error bars. Substitution into Y=mx+c
