Mechanics: Chapter 8 - Modelling Mechanics Flashcards
What assumption is made with Air Resistance
The friction an object experiences as it moves through space.
What assumption is made with Lamina
An object with two dimensions (length and width), such as a sheet of metal. It’s mass is evenly distributed across a flat surface.
What assumption is made with a Rod
An object with one dimension (length), such as a pole or a beam. It’s mass is distributed along a straight line. It is rigid (does not bend or buckle).
What assumption is made with a Light string
It’s mass is very small (regarded as zero), such as a string or pulley. Tension is the same at both ends of a light string
What assumption is made with a Smooth surface
This assumes there is no friction between this surface and an object
What assumption is made with a Wire
A rigid, thin length of metal, treated as one dimensional, either smooth or rough
What assumption is made with a Rough surface
This takes into account friction on surfaces
What assumption is made involving Particles
Dimensions of the object are negligible. It’s mass is concentrated at a single point. Air resistance and rotational forces can be ignored
What assumption is made with a Uniform Body
It’s mass is evenly distributed. It’s mass is concentrated at the geometrical centre of the body (centre of mass)
What assumption is made with Gravity
The force of attraction to the Earth, measured at 9.8m^-2. It is uniform and acts vertically downwards.
(USE 9.8 IN MATHS, USE 9.81 IN PHYSICS)
What assumption is made with an Inextensible string
Does not stretch under a load. Acceleration is constant in objects connected by a taut inextensible string.
