Chapter 4: Thermal Energy & Work Flashcards
What did Hero of Alexandria do?
He drew and described or envisioned the Steam Engine.
What did Thomas Savery do?
- He built the first practical machine to pump water from mines.
- He patented the 1st practical steam engine. (1698)
What did Newcomen do?
- He invented or made a much enhanced steam engine which is called the atmospheric pressure.
- It relied on atmospheric pressure to push the piston down however all pumps depend on Atmospheric Pressure to put the water up the mine
- It had several issues with efficiency and reliability.
What did James Watt do?
- He patented a new steam engine. (was asked to repair Newcomen`s steam engine).
His engine was called the “DOUBLE-ACTING” engine. Since the piston was driven in both directions by steam pressure.
What is Industrial Revolution?
When the Double-Acting could be used to turn a wheel.
What did Charles Pearson do?
He patented the steam turbines which is the steam turbines of today.
Steam-turbine engines do not use pistons.
However, steam passes through a set of curved blades which are similar to fan blades.
They are somewhat cone-shaped. This shape permits the steam pressure to decrease gradually.
What are the 4 Elements?
Earth, Air, Fire and Water
What is Phlogiston?
Substances which could burn included an invisible fluid.
What is Caloric Theory?
A massless fluid which was found in all substances.
Stuff about Caloric
- It could not be created or destroyed, however could flow from one substance to another.
- Caloric always flowed from warmer objects to cooler objects.
What was Rumford`s observation?
Caloric did not exist however heat is equivalent to energy.
What was Mayer`s observation?
The color of venal blood of people in the tropics.
What is Kinetic-Molecular Theory?
The present theory of heat.
What is Thermodynamics?
The field of physics which deals with forces and motion including heat .
What is the first law of Thermodynamics?
Energy cannot be created or destroyed however it can be transformed from one form to another or transferred from one object to another.
What is the second law of Thermodynamics?
It is not possible to remove thermal energy from an energy source and convert it entirely to work.
No process can be 100 % efficient. Some energy will always remain in the form of thermal energy.
Thermal energy always flow spontaneously.
What is the Formula for Work?
W (Work) = F (Force) x D (Distance)
What is the Formula for the area of a triangle?
A = 1/2 b (base) x h (height)
What is the Formula for the area of a rectangle?
A = l (length) x w (width)
What are the 4 steps of the cycle of the piston?
a - Intake Stroke
b - Compression Stroke
c - Power Stroke
d - Exhaust Stroke
What is the Intake Stroke?
The intake valve opens, and the piston moves downward, drawing the mixture of air and fuel into the cylinder.
What is the Compression Stroke?
The intake valve closes and the piston moves up, compressing the air-fuel mixture.
What is the Power Stroke?
When the piston is almost at the top of the cylinder, the spark plug produces a spark that ignites the mixture. The mixture burns, causing hot gases to expand and move the piston down.
What is the Exhaust Stroke?
The piston moves up, forcing the waste products from the combustion of the mixture of the exhaust valve.
