Engineering Science Flashcards
What are the effects of too high viscosity?
- Reduced wear
- Increase power loss
Requires more energy to flow as it is too thick
What are the effects of too low viscosity?
- Increase wear
- Decrease power loss
Describe static friction
Between 2 stationary objects in contact
Describe Kinetic friction
- Sliding- 2 solid surfaces moving against each other
- Viscous- between solid and a fluid (increase as solid acclerates) Known as viscous drag
What is the coefficient of friction?
μ = F/N, where F is the frictional force and N is the normal force.
Define a simple machine..
A device that changes direction or magnitude of a force.
eg; Levers,gears or a pulley system
What is the coefficent of density?
ρ
Define a moment?
The turning effect of a force
Define viscosity
Measure of a fluids resistance to flow
Define couple
A pair of forces acting in equal & opposite force from each other
Define friction
Force that opposes the sliding motion of two surfaces in contact (measured in Newtons)
List the factors that affect friction
- Materials
- Forces applied
- Lubrication
Define relative density
The ratio of density compared with the density of water (1000kg/m3)
It is a ratio
eg;7000kg/m3 cast iron relative density = 7
7000/1000=7
What is the unit of density?
kgm3
Name 4 examples of a simple machine
- Gears
- Lever
- Pulley system
- Brakes
