18/5/08 …12 Jamadilawal 1429H hro,SmscMuzaffarSyah,Melaka HRO The ability to reason by identifying and analysing common characteristics or variables involve, and synthesis the common characteristic or relation with variables to create a physics concept.. CONCEPTUALISATION ELEMENT
Construct: Conceptualize 1. Make and state the observation - Observation skill & critical thinking 2. Make comparison - State the similarities and differences 3.State the relationship -from the similarities and differences or state the principle/law involved.
1 ) State the identical characteristic shown in the diagrams below and relate the relationship between their focal lengths and the curvature of mirrors SPM 2004 5 marks Curved mirror J Curved mirror K Diagram 1.1Diagram 1.2 CONSTRUCT: Conceptualization Skill Paper 2 - Section B (Question 9 / Question 10)
- mirror K is more curve / K is more concave - Reflection rays is focused at a point /F - The light focus point in mirror K is closer then mirror J - Focal length is distance between F and P - Curvature increase focal length decrease // / inversely propotional 5 marks Suggested answer
Problem Solving - Quantitative Section C: Q11/12) Write all the information again. Use symbols. Choose the formula. Make substitution Final answer with correct unit
1.The specification of a frying pan is 240V 1000W. Calculate the time taken for the frying pan to heat up 1000 cm 3 cooking oil from the temperature 30 o C to 120 o C. Assume that all the electrical energy was used to increase the temperature of the oil only and no heat loss to the surrounding. [Specific heat capacity of oil is 2000 J kg –1 o C –1, Density of oil is 800 kg m -3 ] [5 marks] Problem Solving - Quantitative (Paper 2 Section B: Q9/10)
Model Answer Given: P = 1000W V = 240 V Volume = 1000 cm 3 = 1000 x 10 -6 m 3 θ = 120 – 30 = 90 o C. c of oil = 2000 J kg –1 o C –1, Density of oil = 800 kg m -3 Mass,m = 800 x 1000 x10 -6 = 8 x 10 -1 kg t = ? Solution: Heat supplied by heater = heat received by the oil By using formula: pt = mcθ 1000(t) = (8 x10-1) x 2000 x 90 t = 144 s
Problem Solving- Qualitative (Paper 2 Section B: Q9/10) 1. Diagram below shows a saloon car. Ahmad want to modify the car to be a safety racing car. State the modifications to be done by Ahmad and give a suitable physics concept for every of the aspect below: (i) Safety (ii) Shape (iii) Power (iv) Stability (v) Mass [10 marks]
SuggestionRationale 1 The front shape is long // The steering of the car is elastic 2 To lengthen the time of impact // impulsive force is reduce Any 5 correct 3 Shape Aerodynamic // The frame of the car is hard and stiff 4 To reduce the air resistance // stiff / hard to bend 5 Power High engine power 6 Produce high acceleration // Bigger force 7 Stability Wide tyre // Lower the cars body // fix spoiler to the car 8 Low center Of Gravity 9 Mass Low density material but stiff and strong // no added material 10 Maximum acceleration/speed TOTAL10 OR:
DECISION MAKING STEPS 1.Distinguish the characteristics given 2.Explain the properties of every chosen characteristics and give the reason. 3. Distinguish the most suitable material based on the characteristics stated. 4.Give reasons why the material chosen.
DONT WRITE THE CRITERIA FOR ALL THE CHOICE GIVEN IN THE QUESTION DONT STATE VALUE DONT COMPARE BETWEEN THE CRITERIA DONT WRITE THE CRITERIA FOR ALL THE CHOICE GIVEN IN THE QUESTION DONT STATE VALUE DONT COMPARE BETWEEN THE CRITERIA Section C : DECISION MAKING NOTE
DO WRITE EACH CRITERIA FOR THE CHOSEN SUBJECT DO STATE THE CHARACTERISTIC AS HIGH / LOW /LARGE /SMALL DO THE JUSTIFICATION BY REPEATING ALL THE CHARACTERICS OF THE CHOSEN SUBJECT. DO WRITE EACH CRITERIA FOR THE CHOSEN SUBJECT DO STATE THE CHARACTERISTIC AS HIGH / LOW /LARGE /SMALL DO THE JUSTIFICATION BY REPEATING ALL THE CHARACTERICS OF THE CHOSEN SUBJECT. Section C : DECISION MAKING NOTE
Decision Making Skill(P2-Section A: Q 8; Section C: Q 11/12) For every metal properties in the table above, explain the suitability of the properties tobe used as a material to make a frying pan. Hence determine the most suitable metal to make the frying pan. Give the justification for your choice. [10 marks] Metal Spec. heat capacity / J kg –1 o C –1 Melting point / o C Density/ kg m -3 Rate of Rusting P45015407873High R8806602698High S51016207800 Do not Rust T39896110500Medium U3779788400 Do not rust Q 1) As a researcher you are assign to investigate the properties of the metal in the table to be used as the material to make a quality frying pan.
PropertiesExplanation Low specific heat capacity Easily to be hot High melting point Can sustain high temperature Low density lighter lighter Low rate or rusty S is chosen So that it do not rust Because of low specific heat capacity, high melting point, low density and low rate of rusty. OR: