Energy
What is energy?
Energy is everything that produces change or transforms objects
What is a simple machine?
Simple machines have no or very few moving parts. Human energy is needed to make them function
What is a compound machine?
A compound machine is made of two or more simple machines. Each part or component carries out a different function.
How does an electrical engine work?
In an electrical engine, magnets are placed around cables. When electricity flows down the cables and reaches the engine, the magnets turn. This movement is then transmitted using a belt or an axle to the other components of the machine
Who is the earliest inventor that we know about?
And what did he study?
Archimedes.
He studied how objects travel through the air
What is luminous energy?
It´s main source is the sun, but it has other sources, such as fire and light bulbs
What is an inclined plane?
It needs less effort to push a heavy object up a slope, than to lift it to a higher level, so that is why we use an inclined plane
What is a mechanism?
Mechanisms combine the force of two or more simple machines. This means that it is eaier to carry out the task
How does a combustion engine work?
Fuel, such as petrol, is needed for a combustion engine. A spark starts the fuel burning. The force produced by the burning of the fuel pushes the moving components. The combustion produces gases which are expelled out of the machine. Combustion engines are used for many large vehicles.
What did Archimedes invent?
The catapult, the claw, the archimedes screw
What is electrical energy?
It can be stored in batteries. It is also found in storm clouds and lightning
What is a lever?
A lever has a fixed support point or fulcrum and a rigid bar. A force downwards on one end of the bar is transferred to the other end. Because of the position of the fulcrum, the force is increased
What is transmission?
To combine the force of two simple machines, the movement of the machines needs to be linked or transmitted.
Why are machines with a combustion engine almost always used outdoors?
They are used otuside for safety, to avoid causing a fire, or breathing in harmful gases
What century was Isaac Newton from?
17th century
What is mechanical energy?
It can be observed when an object changes position
What is friction and how does it help us to move objects more easily along the ground?
When we push an object along the ground, the contact between the object and the ground creates a force called friction. This ground creates a force called friction. This force works in the opposite direction of the movement. Wheels and rollers turn easily. When we place a heavy object on top of them, the friction with the ground is reduced and it is easier to move the object
What is an axle?
Axles connect two wheels. When one wheel turns, the force is transmitted along the axel making the other wheel turn
Give an example of a machine with an electrical engine?
Washing machine, fridge, trains, cars
Why was Isaac Newton important?
He developed a theory to explain the force of gravity, which helped us to understand the movement of planets around the Sun. He devised the three laws of motion, which have been used in mechanical engineering ever since
He also invented the reflecting telescope
What is chemical energy?
It is the energy stored in matter. It can be released from materials, such as fuels and food
What is a pulley and how does it work?
A pulley is a machine that uses wheels to lift an object. The wheel is attached to a high position. A rope is attached to a heavy object and then passed around the wheel. When we pull down on the rope, the object moves upwards. By adding more wheels, the amount of force we need to life the object is reduced
What are gears?
Gears are wheels, usually of different sizes, that work in pairs. The wheels have teeth that interlock. When one wheel turns, it forces the other wheel to turn in the opposite direction
How do electrical machines get their energy?
From either batteries, or the main supply of electricty which comes into the house
What did Marie Curie discover?
She discovered two new chemical elements, Polonium and radium. She measured the amount of x-rays emitted by these elements and defined the term radioactivity. Radium is used in some cancer treatements today