1. Edwina De Guzman
III-SSC
1. Specific Heat of Elements
2. Cycles in Gasoline Engine
1. Intake Stroke - The inlet valve is opened and the fuel/air mixture is drawn in as the piston
travels down.
2. Compression Stroke - The inlet valve is closed and the piston travels back up the cylinder
compressing the fuel/air mixture. Just before piston reaches the top of its compression stroke
a spark plug emits a spark to combust the fuel/air mixture. The number of degrees before the
top its stroke is the ignition advance. When the piston is at the top of its travel it is at top
dead centre (TDC).
3. Combustion Stroke - The piston is now forced down by the pressure wave of the
combustion of the fuel air mixture. The engines power is derived from this stroke.
4. Exhaust Stroke - The exhaust valve is opened and the piston travels back up expelling the
exhaust gases through the exhaust valve. At the top of this stroke the exhaust valve is closed.
This process is then repeated.
Substance
Specific Heat Capacity
at 25oC in J/goC
H2 gas 14.267
He gas 5.300
sodium 1.23
magnesium 1.020
aluminum 0.900
potassium 0.75
sulphur 0.73
calcium 0.650
iron 0.444
nickel 0.440
zinc 0.39
copper 0.385
sand 0.290
silver 0.240
tin 0.21
lead 0.160
mercury 0.14
gold 0.129

2. Kesha Mae Sagaoinit
III-SSC
1. Specific Heat of Different Elements
2. Cycles in Gasoline Engine
1. INTAKE: this stroke of the piston begins at top dead center. The piston descends from the top of
the cylinder to the bottom of the cylinder, increasing the volume of the cylinder. A mixture of fuel
and air is forced by atmospheric (or greater) pressure into the cylinder through the intake port.
2. COMPRESSION: with both intake and exhaust valves closed, the piston returns to the top of the
cylinder compressing the air or fuel-air mixture into the cylinder head.
3. POWER: this is the start of the second revolution of the cycle. While the piston is close to Top
Dead Centre, the compressed air–fuel mixture in a gasoline engine is ignited, by a spark plug in
gasoline engines, or which ignites due to the heat generated by compression in a diesel engine.
The resulting pressure from the combustion of the compressed fuel-air mixture forces the piston
back down toward bottom dead centre.
4. EXHAUST: during the exhaust stroke, the piston once again returns to top dead centre while the
exhaust valve is open. This action expels the spent fuel-air mixture through the exhaust valve(s).
Substance
Specific Heat Capacity
at 25o
C in J/go
C
H2 gas 14.267
He gas 5.300
sodium 1.23
magnesium 1.020
aluminum 0.900
potassium 0.75
sulphur 0.73
calcium 0.650
iron 0.444
nickel 0.440
zinc 0.39
copper 0.385
sand 0.290
silver 0.240
tin 0.21
lead 0.160
mercury 0.14
gold 0.129