Topic 1 Flashcards
What is a simple machine?
A mechanical device that can transmit, change magnitude or direction of a force
What are the 6 simple machines?
- lever
- wheel and axle
- pulley
- inclined plane
- wedge
- screw
What is a basic machine?
a modified simple machine or a machine using only several simple machines
What is linear motion?
motion in a straight line in a horizontal or vertical direction
What is rotary motion?
motion in a continuously circular path that is about an axis
What is oscillatory motion?
repeated motion where the same movement is repeated
What is reciprocal motion?
repetitive back and forth or up and down linear motion
What is using motion?
utilises various types of motion
What is the motion of a rocking chair?
oscillating
what is the motion of a gear?
rotary
What is the motion of a saw?
reciprocal
What is Mechanical Advantage?
The ratio of the force produced by a machine to the force applied to it
What is Velocity Ratio?
The ratio of the distance moved by effort to the distance moved by the load in a simple machine.
What is efficiency?
The measure of how much work goes into moving something compared to mechanical advantage.
If the input force is 80N and the output force is 160N. Calculate mechanical advantage
2
if something moves 200mm when the effort moves 600mm. Calculate velocity ratio
3
What is a first order lever?
the fulcrum is between the effort and the load
What is a second order lever?
the load is between the fulcrum and the effort
What is a third order lever?
the effort is between the load and the fulcrum
Is a driver gear the effort or load?
effort
Is a driven gear effort or load?
load
What are three types of gears?
- spur
- worm and worm gear
- rack and pinion
How do you calculate the VR of a spur gear?
number of teeth on driven/number of teeth on driver
How do you calculate the VR of a worm gear?
number of teeth on worm gear/number of threads on worm
How do you calculate the VR (gear ratio) of a rack and pinion?
number of teeth on pinion x number of teeth on rack
What is the VR of a pulley system?
number of ropes supporting the load
what is work?
the energy transferred to or from an object via the application of force along a displacement.
What is the SI unit of work?
Joules
What is energy?
the ability/capacity to do work
what is kinetic energy?
the energy that an object possesses due to its motion
what is potential energy?
the energy that an object possesses because of its position in a gravitational field
what is mechanical energy?
the sum of the kinetic and potential energy of an object that is used to do work
What is power?
the rate of energy consumption over time/rate of doing work
What is power measured in?
Watts
what is energy consumption measured in?
1 joule per second (J/s)
What is displacement?
change in the position of an object, along a straight line
What is friction?
a force that opposes motion or impending motion
Does a low or high coefficient of friction allow an object to move more easily?
low
how can you find the MA of an inclined plane?
MA= incline length/incline height
what is a formula for efficiency?
output power/input power
