Key Terms - Mechanics Flashcards
What is a Particle?
Dimensions of the object are negligible. It’s mass is concentrated at a single point. Air resistance and rotational forces can be ignored.
What is 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 is a 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 is an Uniform Body?
It’s mass is evenly distributed. It’s mass is concentrated at the geometrical centre of the body (centre of mass).
What does Light mean?
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 does Inextensible mean?
Does not stretch under a load. Acceleration is constant in objects connected by a taut (inextensible) string.
What does Smooth mean?
This assumes there is no friction between this surface and an object.
What does Rough mean?
This takes into account friction on surfaces.
What does a Wire mean?
A rigid, thin length of metal, treated as one dimensional, either smooth or rough.
What is Air Resistance?
The friction an object experiences as it moves through space.
What is Gravity?
The force of attraction to the Earth, measured at 9.8ms^-2. It is uniform and acts vertically downwards.
