L1 & L2
What is a mechanical device?
Devices that help humans do work and use energy more effectively.
Name all 6 simply machines.
Lever, incline plane, wedge, screw, pulley, wheel and axle.
Gears with teeth that link into chains are called...
Sprockets.
What are the two categories energy sources go into?
Non-renewable and renewable.
How is friction created?
Two opposite motions against each other.
What is an example of a mechanical device used in the past and present?
Whats 3 examples of a wedge?
Anything with a blade, axe, knife, scissors, saws, nails, chisel or even a pin.
Which involves a liquid? Pneumatics or hydraulics?
Hydraulics.
What are the two types of energy?
Potential and kinetic.
Whats the equation for efficiency?
MA
_____ X100%
SR
Which machines used animals to power it? The persian wheel, archemedes screw or both?
Persian wheel.
Define a subsystem.
A part of a whole machine that includes certain parts working together to do a certain job.
In hydraulics and pneumatics, what does P,F,A stand for?
P= pressure, F= force, A= area.
What is the equation for mechanical advantage?
MA= output force (N)
________________
input force (N)
What is the scientific definition of work?
The definition of work is when force acts on an object to make the object move.
What machine was more effiencent? The persian wheel or archemedes screw?
The archemedes screw.
Is a door stopper an example of a incline plane or a wedge?
A wedge.
Gears with interlocking teeth rotate in what direction?
Opposite.
What is the equation for speed ratio?
SR= Input distance
_________________
Output distance
What is the equation for work?
Work = Force x Distance.
Whats each mechanical device designed to meet?
Each machine is designed to meet a basic need.
What makes a bike a complex machine?
Brakes - they use a lever to increase the force you apply with your hands.
Pedals - Act as a lever increasing the force you apply to the wheel and axle.
What is a rube goldburg machine?
Multiple simple machines made up together to do a simple task.
What are 4 main renewable energy sources?
- Geothermal
- Wind
- Biomass
- Hydropower
Is work being applied when pedalling a bike? Yes or no?
Yes.