Statics Flashcards
Define force
Force is that which changes a body’s state of rest or of uniform motion in a straight line.
What is the SI unit of force?
Newton’s
What is the imperial unit of force
Pounds (lb)
What is a moment?
The turning effect of a force.
Formula for a moment
Moment = Force (N) x Perpendicular Distance (M)
Calculate force 2 if
Force 1 = 80N
The distance from F1 is 3m and the distance from f2 is 0.2m
1200
Formula for force
Mass x gravity (10)
Force of gravity?
10
Equation for solving moments
F1 x a = F2 x b
Define torque
The force applied to a body that is provided at a point
What is a couple?
A pair of forces that are equal and opposite but applied at points separated by distance perpendicular to the forces.
- parallel
- equal magnitude
- opposite direction
What is a vector and give an example
They have a direction and a magnitude.
Eg - Force, velocity, acceleration, displacement, weight
What is a scalar quantity?
Give an example
Have a magnitude but no direction.
E.G, speed, mass, distance, volume
What is the centre of gravity?
The point about which the body is perfectly balanced. (Geometric centre)
What is stress?
Pressure over an area. It produces deflection or deformation in the material.
What are the 5 different types of stress
Tensile Compressive Torsion Shear Bending
What is tensile stress?
Axial or normal stress.
What is Hooks Law?
Stress is directly proportional to strain.
The formula for hooks law?
F (fish thing) K
What is linear region?
When it can go back to its original state.
What is the plastic region
Where it cannot go back to its original state
What is Young’s modulus and units
Stress / strain = strength
Same unit as stress
The formula for stress
Force/area
How to calculate bulk modulus
Pressure/volumetric strain
Formula for bulk modulus
Force/area x original volume/ Change in volulme
Nm2
How to work out volumetric strain
Change in volume/ original volume
3 types of strain
Axial
Volumetric
Transverse
What is transverse strain
Change in diameter / original
What is bending?
Combination of tension and compression
Define hardness
High resistance to indentation
Define toughness
Ability for a substance to resist breakage when deforming or impact forces are applied
Define malleability
Can be beaten rolled or pressed into shape
Define brittleness
Break with little or no change or shape
Define ductility
Stretched into new shapes without pulling apart and will keep their new shape
Define vapour
Gas that can be liquified by an increase in pressure not temp
Define toxicity
Poison
Define inert
Will not chemically combine with another substance
What is buoyancy?
When an object is submerged in liquid the object displaces a volume of liquid equal to its volume
What is Archimedes principle?
A body will float in any liquid that has a weight density greater than the weight density of the body.
What is the equation for buoyancy ?
Fb = Vs x D x G
