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• mass of the object - m
• f = force
• Heat can be transferred in three basic mode : conduction, convection, radiation
• Conduction - the transfer of energy from the more energetic particles of a substance to the adjacent less energetic ones as a result of interactions between the particles.
• Convection - The mode of energy transfer between a solid surface and the adjacent liquid or gas that is in motion, and it involves the combined effects of conduction and fluid motion.
• Forced convection - if the fluid is forced to flow over the surface by eternal means such as a fan,pump, or the wind
• Radiation - The energy emitted by matter in the form of electromagnetic waves as a result of the changes in the electronic configurations of the atoms or molecules.
• Thermodynamics - is a branch of physics that deals with heat and temperature and how they are related to work and other forms of energy.
• Heat engines - A device that converts heat to mechanical energy, which can be used to do work.
• The four stroke engine was first demonstrated by - Nikalaus Otto in 1860, it is also known as the Otto cycle.
• Four operations of Four-Stroke Engine ; intake,compression,combustion and exhaust
• Intake - the intake valve opens, causing air and gasoline to enter the engine. Gases combine with the fuel. This causes the pistol to travel down.
• Compression - The intake valve closes, while the piston travels up, causing the mixture of air and fuel to be compressed. at this point, the air-fuel mixture is at a very high temperature.
• Combustion - The spark plug ignites the air-fuel mixture, causing an explosion. This pushes the piston back down again.
• Exhaust - The exhaust valve opens, while the piston goes back up. This causes the exhaust gases to be expelled as smoke.
• Efficiency - The measure of how well an engine converts heat into useful work. It is the ratio between the work done by the system and the amount of heat put into the system.