UNIT D STUDY DECK Flashcards
What is a simple machine
A tool or device made up of one basic machine
What are the 6 simple machines
Lever, inclined plane, wheel and axle, wedge, screw, pulley
What is an example of a lever
Scissors
What is an example of an inclined plane
A ramp
What is an example of a wheel and axle
Screwdriver
What is an example of a wedge
Axe
What is an example of a screw
Corkscrews
What is an example of a pulley
Window blinds
How many classes of levers is there
3
What are the 3 classes of levers
Class 1, class 2, class 3
How to tell if a lever is a class 1
The fulcrum is in the middle of the load and effort
How to tell if a lever is a class 2
The load is in the middle between the fulcrum and effort
How to tell if a lever is a class 3 lever
If the effort is in the middle between the fulcrum and load
Give 3 examples of a class 1 lever
Scissors, seesaw, crowbars
Give 3 examples of class 2 levers
Wheelbarrow, nutcracker, nail clippers
Give 3 examples of class 3 levers
Brooms, hockey stick, fishing rod
What is a complex machine
Devices made up of several simple machines working together
What are the 4 effects of simple machines
Change the direction of applied force
Multiply force
Increase or decrease speed
Transfer force
What is a system
is a group of parts that work together to perform a function
What is a subsytem
is a smaller group of parts that performs a specific function within a complex machine
What are the 2 systems that transfer forces
Linkages and transmissions
What is a linkage
A belt or chain used to transfer energy
What is an example of a subsystem
Engine in a vehicle
What is an example of a system
A bike
When one wheel turns___________.
The other will turn in the same direction
What is a transmission
A type of linkage used for heavier loads
What is the gear that has the force applied
The driving gear
What is the force that is applied from the driving gear called
The driven gear
What are the options of transmissions
Move the object slowly with a big force
Move the object faster with a smaller force.
What is a gear train
A set of 2 or more gears in rotation
The smaller the gear, the faster it will go
True
What is the difference between the multiplying gear and the reducing gear
The multiplying gear increases speed while the reducing gear decreases speed
Mechanical Advantage meaning
The amount in which the MACHINE can multiply a force
What is the INPUT force
The force you apply
What is the OUTPUT force
The force the machine applies
Speed ratio meaning
A measure of how the speed of the object is affected by a machine
True or false:
The input and output for speed ratio is called the input and output distance
True
Can you have a mechanical Advantage less than 1
Yes
It means that the machine is better for speed, not force
What will not be affected when friction if involved
Speed ratio
What does it mean when someone says ‘ideal situation’ in science
A frictionless world
What is efficiency
is a measure of how well a machine or a device uses energy
What happens when work is done
A force acts upon an object to make it move
Without energy there is no ______
work
What do simple machines do
The decrease the amount of effort
What do simple machines NOT do
Decrease the amount of work
What is a hydraulic system
Uses liquids under pressure to move loads
What is pascal’s law
Pressure is all the same in an enclosed fluid
On a piston, pressure exerts on the _______________
Output piston
On a piston, the input piston is used to apply ________
Force
What are some of the criteria people use to evaluate a machine
Use
Aesthetics
Purpose
Cost
Workmanship
Reputation
What is the tradeoff
Force for distance
What is efficacy
How quickly a device does it’s task
What is effectively
How well a machine does it’s job
What must a design do
Fit the function
What is a function
What the device is supposed to do
What is a design
The form that the machine has to make is usable
What are the 2 questions you ask when evaluating
How can we improve it
How can we make it better for the environment
