Materials Flashcards
Describe how you can use instruments available in a physics laboratory to determine the pressure exerted by the cylinder on the table. State how you would make your results as precise as possible.
pressure =
weight (of cylinder)/
area
Weight (of cylinder) determined using a newtonmeter
Area determined by measuring the diameter with a micrometer and then using (area =) pi × r^2
A sensible suggestion that reduces the % uncertainty:
Use micrometer / (vernier) calipers / travelling microscope
Use balance / newtonmeter with smaller division (AW)
What is archemodies principle
whena body is partially or completely submerged in a fluid…
The upthrust is equal to the weight of the fluid it has displaced
Energy per unit volume on graph for stress strain graph
Energy per unit volume= (1/2 )(stress)(strain)
Stress
Force/area(cross sectional)
Strain
Extension/length
What do stress strain graphs look like for ductile materials
Stress strain graphs for ductile materials curve
What do stress strain graphs for brittle materials look like
stress strain graphs for brittle materials don’t curve
Elastic deformation meaning
Material returns to original shape once forces are removed
Plastic deformation
Material is permanently stretched
Tensile strain meaning
and
tensile stress meaning
tensile strain: Change in length
tensile stress: force applied
What is the ultimate tensile strength
The maximum stress a material can take
What is the young modulus
The measurement of the stiffness of a material
What happens when an object is brittle
There is elastic behaviour up until the breaking point it will not deform before breaking
What happens when a material is ductile
There will be elastic and plastic regions before the material breaks
