chapter 8 - year 1 Flashcards
1
Q
what are the modelling assumptions of particles
A
- mass is concentrated at a single point
- rotational forces and air resistance can be ignored
2
Q
what are the modelling assumptions of a rod
A
- mass is concentrated along a line
- no thickness
- rigid
3
Q
what are the modelling assumptions of the lamina
A
- mass is distributed across a flat surface
4
Q
what are the modelling assumptions of a uniform body
A
- mass of the object is concentrated at a single point at the geometrical centre of the body - the centre of mass
5
Q
what are the modelling assumptions of a light object
A
- treat object as having zero mass
- tension the same at both ends of the a light string
6
Q
what are the modelling assumptions of a inextensible string
A
- acceleration is the same in objects connected by a taut inextensible string
7
Q
what are the modelling assumptions of a smooth surface
A
- assume that there is no friction between the surface and any object on it
8
Q
what are the modelling assumptions of a rough surface
A
- object in contact with the surface experience a frictional force if they are moving or are acted on by a force
9
Q
what are the modelling assumptions of a wire
A
- treated as one dimensional
10
Q
what are the modelling assumptions of a smooth and light pulley
A
- pulley has no mass
- tension is the same on either side of the pulley
11
Q
what are the modelling assumptions of a bead
A
- moves freely along a wire or string
- tension is the same on either side of the bead
12
Q
what are the modelling assumptions of a peg
A
- dimensionless and fixed
13
Q
what are the modelling assumptions of air resistance
A
- usually modelled as being negligible
14
Q
what are the modelling assumptions of gravity
A
- assume that all objects with mass are attracted towards the Earth
- Earth’s gravity is uniform and acts vertically downwards
- g is constant and is taken as 9.8 m/s2 (unless otherwise stated)
