Modelling assumptions Flashcards
What is gravity?
The force of attraction between all objects.
Give assumptions of gravity.
.Assume all objects with mass are attracted to earth
. Earths gravity is uniform and acts vertically downwards.
What is air resistance?
resistance experienced as an object moves through the air.
Give an assumption of air resistance.
Usually modeled as being negligible.
What is peg?
A support from which a body can be suspended or rested.
Give an assumption of peg.
. dimensionless and fixed
. can be rough or smooth
What is bead?
a particle with a hole in it for string or wire.
Give an assumption of bead.
. Moves freely along a wire or string
. tension is the same on either side of the bead.
What is smooth and light pully?
They are a pully that are smooth and light.
Give an assumption of a smooth and light pully.
.pully has no mass
. tension is the same on either side of the pully.
What is a wire?
rigid thin length of metal.
Give an assumption of a wire.
. treated as one-dimensional.
What is a rough surface?
when a surface is not smooth.
Give an assumption of a rough surface.
.objects in contact with the surface experience friction if they are moving.
Give an assumption of a smooth surface.
assume that there is no friction between the surface and object.
What is an inextensible string?
a string that doesnt stretch.
Give an assumption of an inextensible string.
. acceleration is the same in objects connected by an inextensible string.
What is a light object?
mass of the object is small compared to other masses.
Give an assumption of a light object.
. treat object as having zero mass
What is a uniform body?
mass is distributed evenly
Give an assumption of a uniform body.
mass of the object is concentrated at a single point- the center of mass.
What is a Lamina?
object with area but negligible thickness like a sheet of paper.
Give an assumption of a lamina.
mass is distributed across a flat surface
What is a rod?
all dimensions but one are negligible like a pole or beam.
Give an assumption of a rod.
. mass is concentrated along a line
. no thickness
What is a particle?
dimensions of the object is negligible.
Give an assumption of a particle.
mass of the object is concentrated at a single point.
