Post on 31-Dec-2015
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PAPER 2 SECTION A
ZULAILI BT YAACOB
QUESTION 4WHICH CHAPTER ?
WHICH PRINCIPLE OR LAW
HOW MANY MARK /S
EXPLAIN : WHY
1 – PRESSURE INVERSELY PROPORTIONAL TO VOLUME 2 – PRESSURE AT SURFACE IS DECREASES, VOLUME OF AIR IS INCREASES
BOYLE’S LAW
Fresh water replace by higher density?
Density higher pressure higher ( P = ρgh)
Pressure higher volume less
The volume will decreases at R.
An air bubble of volume 5 cm3 is released by an air pump at depth of 0.5 m. Calculate the volume of the air bubble when it reaches the surface of the water.[ Assume that the atmospheric pressure is 10 m water ]
EXTRACT INFORMATION FROM QUESTION :
V1 = 5 cm 3 , depth = 0.5 m, atm pressure = 10 m
P 1 V 1 = P2 V2
Depth = 0.5, atm pressure 10 m P1 = 0.5 + 10 = 10.5 m
P2 = 10 m
V2 = (P 1 V 1) / P2
V2 = ( 5 x 10.5) / 10
= 5.25 cm3
WHICH CHAPTER ?
Forces and motion
Observed diagram Info from diagram :
High ram , low rampGraph of velocity vs time
Quantity by the gradient
Velocity ms-1
Time s
Unit ms-2
acceleration
Comparing gravitational potential energy :
The gravitational potential energy in diagram 5.1 is higher compare to diagram 5.2
Comparing velocity :
Velocity of diagram 5.1 is greater compare to diagram 5
Comparing kinetic energy:
Kinetic energy of diagram 5.1 is higher compare to 5.2
Relationship between gravitational energy and kinetic energy
When the gravitational energy increases, the kinetic energy increases
Physics concept :
Conservation of energy
Skate from Z to Q
Velocity decreases
Kinetic energy at Z > Kinetic energy at Q
Q = mcθ
High
low
Need Q more
Meaning :
The amount of energy needed to increase the temperature of 1 kg materialby 10 C or 1 K
Cooking rapidly : material :
copper Spesific capacity low
Material for handle : polymer
insulator
Mass of the pot :Low mass
Easy to carry
•The pot are heated by using an electric hot plate of power 800 W.
Based on the information in table 8 , calculate the time to achieve a temperature rise of 900 for :
Extract information from given statement.P = 800 W, m = 3.5, θ = 900Pt = mc θ
t = (mc θ) P
354.4 s / 5.91 min
109.7 s / 1.83 min
PAPER 2 SECTION B
Weight : Force exerted on every object
Compare weight of the boy with his father : The weight of his father is greater than the boy
The volume of water displaced :
The volume of water displaced by ball B is greater than ball A
The buoyant force acted on them
The buoyant force acted on the father is greater than the boy
Relationship buoyant force and volume of water displaced
When the water displaced increases, the buoyant force increases
Relationship buoyant force and weight of water displaced
When the weight of water displaced increases, the buoyant force increases
Archimedes principle
Explain why the wooden block moves upwards and then floats on the water surface
Bouyant force increases when the volume of Immersed wooden blockincreases
Wooden block moving upwhenBuoyant force > weight
B . F equals to weight,the wooden block is floating
Design a raft to accommodate 15 participant and able to move quickly
Aspects Suggestions reasons
Shape of the raft
Material for the raft
Size of the raft
Design of the raft
streamline Reduce water resistance
Low density Can float easily
Bigger size Can accommodate all participant
Layers of bamboo Higher buoyant force
Attach big fan / motor /wide sail
Increase the speed