Physics Paper 1 Marking Scheme
KCSE CLUSTER TESTS 26
Physics Paper 1
SECTION A (25 Marks)
Pressure on the bubble reduces as it rises to the surface of water,
1 marks
2 marks
Many electron are involved in heat transfer with minimal heat loss
1 marks
The weight of masses exert pressure on ice below the wire to melt as is cuts through The melted ice above the wire no long under pressure refreezes, latent heat of fusion is drawn from the wire
2 marks
i) Liquids are incompressible and
ii) Transmit pressure equally.
2 marks
Unstable;^ any push causes the marble to
Roll to lower its CoG
2 marks
i) F = 20N
ii) a (I) Weight/force gravity
(II) Up thrust/viscosity
b) Moves at constant terminal velocity
3 marks
Inter- molecules forces exist between molecules of a real gas unlike in an ideal gas where intermolecular forces don’t exist,√ (1mk)
- in an ideal gas there is elastic collision between molecules whereas in a real gas the collision is inelastic,
2 marks
2 marks
)Methylated spirit vaporizes faster than water drawing latent heat of vaporization from the hand
1 marks
Faster moving air above the wing causes lower pressure above . Higher pressure difference cause a lift effect .
2 marks
The tension in the string reduces because upthrust on the block increase with density
1 marks
2 marks
2 marks
SECTION B (55 Marks)
a) The pressure of on fixed mass of a gas is directly proportional to the absolute temperature provided the volume is kept constant
c) Is the lowest possible temperature on the Kelvin scale;
d) P =phg
8 marks
iii) Some of the potential energy is lost as work done against air resistance;
13 marks
8 marks
a) Is the heat required to raise the temperature of a unit mass of a substance by 1 Kelvin
10 marks
14 marks