Engineering- simple machines Flashcards
What’s engineering?
Anything g that’s been modified or changed, this involves studying, designing, and creating technological objects
What is a simple machine?
This is a device with a few pieces that allows a task to be completed faster or with less effort
Example of simple machine
Elevator
What DONT simple machines do?
They dont reduce the amount of energy needed to do the task they distribute it longer or shorter.
What does a lever do?
A stiff piece that pivots around d something called a fulcrum
Ex; nail clipper, shovel, seesaw
What are the 6 types of different machines?
- lever
- inclined plane
- the pulley
- the screw
- the wedge
- the wheel and axel
What is a fulcrum?
In a lever the movable bar can rest on a support called the fulcrum, the fulcrum is known as the PIVOT POINT
Whats a resistance force?
What must be moved or lifted it is also known as the load.
What is The effort force?
It is the force that must then be applied on the lever in order to have work done on. The load.
What is a lever arm or effort arm?
Located between the fulcrum and the effort
What is the load arm or resistance arm?
Is located between the fulcrum and the load
What are the 3 classes of levers?
First class Second class Third class
What is a first class lever?
When the fulcrum is between the force and the load- the further away it is the harder it is to lift (think of a seesaw)
What is the second class lever?
When the load is in The middle - its called as a power lever and is often used when really large distances because it is distributing the weight
Third class lever
When the force is between the fulcrum and the load.
Inclined plains
It’s a slop that reduces the force needed to lift or lower a load over a large distance
What’s a wedge?
2 back to back inclined planes used to exert force on an object- if its not moving something but send to hole something in place its a wedge
What are screws?
An inclined plane the circles an axes- in order for a screw to move it depends on the pitch
What are the parts of a screw?
- Thread
- Pitch
- Shaft
What is a pulley?
A wheel fitted with a cord that is used to help lift and lower loads
When you use more than 1 its called a HOIUST
What is a wheel and axel?
Helps reduce force needed to move an object or to increase the distance an object can travel
What is a motion transmission system?
Is a mechanism that TRANSMITS motion from one part to another without modifying it
What are the 3 motions and what they do?
Rectilinear translation : motion in straight line
Rotational : circular motion
Helical motion: spiral motion
What are the 4 types of motion transmission systems?
- friction gears
- Pulleys and belts
- gear trains
- train and sprocket wheels
What are friction gears
Transmit rotational motion by contact motion by contact friction (rubbing ) between wheels
Pulleys and belt?
Made of 2 or more pulleys (friction gears) and belt
Disadvantage is …if to much force is exerted the belt can slip of the pulleys
Chain and socket wheels?
Made up of toothed wheels connected by a chain, motion is transmitted by teeth and wheels which fit the loops of the chain
Cannot slip off the gears, as a result much more force can be used however all the pieces need to be lubricated
Gear trains?
Made of tooth wheels known as gears that transmit rotational motion (gears)
Used to increase or decrease the speed of motion
Speed depends on size of gears and the number of teeth each gear has.
The smaller the gear it’s faster, the bigger the gear the slower
What’s motion of transformation?
Turns 1 types of motion into another
What are the 3 types of transformation systems?
Rack and pinion
Connecting rod and crank
Cam and follower
What’s a rack and pinion?
Made of a toothed wheel (pinion) and a straight toothed rod (rack)
What’s a Cam and follower
A rotational motion into a bidirectional translational motion
(Back and forth motion)
What is a connecting rod and crank?
It’s a rotational motion to translational its a very fast but you have to lubricate it very often
