Transcript SSSTWOPHYSICS - Faith Academy Otta

SSS TWO PHYSICS
FIRST TERM
HEAT ENERGY
SCHEME OF WORK
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1. MEASUREMENT OF HEAT ENERGY
i) Heat Capacity
ii) Specific Heat Capacity
iii) Determination of Specific Heat Capacities in Solids and Liquids.
2. LATENT HEAT
i) Concept of Latent Heat
ii) Melting Point and Boiling Point
iii) Specific Latent Heat of Fusion and Vaporization.
iv) Dew Point and Relative Humidity
3. THE GAS LAWS
i) Boyle’s Law
ii) Charles’ Law
iii) Pressure Law
iv) General Gas Law
SCHEME OF WORK
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4. PRODUCTION AND PROPAGATION OF WAVES
i) Pulsating System
ii) Mechanical Waves
iii) Energy Transmitted With Definite Speed, Frequency and Wavelength
iv) Wave-Form
v) Mathematical Relationship
vi) Types of Waves
5. PROPERTIES OF WAVES
i) Reflection
ii) Refraction
iii) Diffraction
iv) Interference
v) Polarization
6.CONCEPT OF LIGHT WAVES
i) Source of Light
ii) Propagation of Light
iii) Transmit ion of Light
iv) Sun’s Energy and The Radiation to The Earth
SCHEME OF WORK
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7. REFLECTION OF LIGHT AT PLANE SURFACES
i) Laws of Reflection
ii) Formation of Images
iii) Rotation of Mirrors
iv) Applications of Mirror.
8. REFLECTION OF LIGHT AT CURVED SURFACES
i) Concave and Convex Mirrors
ii) Images Formation on Curved Mirror
iii) Mirror’s Formula
iv) Experimental Determination of Focal Length
DEFINITION OF TERMS
Heat capacity is the quantity of heat required
to change/raise/lower the temperature of a
body by 1K. The unit is Joule per Kelvin.
Specific heat capacity is the quantity of heat
required to raise the temperature of a unit
mass of a substance through unit
temperature. The unit is Joule per Kilogram
Kelvin. The formula is Q = mcϴ
In calorimetry and method of mixture
Heat lost by substance = heat gained by
substance
mcϴ = mcϴ
Specific latent of fusion is the quantity
of heat required to convert a unit mass of
a substance from solid to liquid without
change in temperature.
Mathematically expressed as Q = mL
 When
electrical means of heating is
involved, the formula becomes
 Ivt = mcϴ
 Ivt = mL
 Where L is the constant of
proportionality called the specific latent
heat of fusion or vaporization measured in
Joules per kilogram.
Definition of terms
 Vapour pressure is the pressure exerted by
the molecules of a vapour.
 Saturated vapour is a vapour that is in contact
with its own liquid within a confirmed space.
 Saturated vapour pressure(SVP) is the
pressure exerted by the saturated vapour.
 Dew point is the temperature at which the
water vapour present in the air is just
sufficient to saturate.
Assignment
• A block of lead of mass 100kg in a crucible and at
a temperature of 40 degree Celsius was placed in
an electric furnace rated 10kw. If the melting
point of lead is 320 degree Celsius, calculate the
 (i) quantity of heat required to heat the lead to its
melting point.
 (ii) additional heat energy required to melt the
lead.
 (iii) time taken to supply this additional energy
specific heat capacity of lead = 120J/kgk, specific
latent heat of fusion of lead = 25000J/kg.