Chapter 8 Modelling In Mechanics - Year 1 Flashcards
Air Resistance
The friction which an object experiences through space (not astronomy space but any space)
Lamina
A 2 D shape (length and width) which has mass which is evenly distributed across a flat surface
Rod
An object with 1 dimension. It is rigid and therefore doesn’t bend of buckle.
There is no thickness
Light
Mass which is regarded as 0
As a result tension is the same at both ends of a light object (for example a light string)
Smooth
There is no friction between the smooth object and objects touching it.
Wire
A rigid thin length if metal. It is treated as a 1 dimensional object. It can be smooth or rough.
Rough
This means that something has friction
Particle
The dimensions of an object are negligible as a result of this air resistance and rotational forces can be ignored.
It’s mass is concentrated around a single point
Uniform body.
The mass is evenly distributed. The mass is concentrated at the geometric centre of the body (the centre of mass)
Gravity
Is uniform at 9.8m/s2
It acts vertically downwards
Inextensible
It don’t stretch.
If something is inextensible then acceleration is constant throughout the object.
What is negative acceleration called?
Deceleration or Retardation
What is the dimension of displacement?
Length
What is the dimension of distance?
Length
What is the dimension of velocity?
Length ÷ Time
What is the dimension of speed?
Length ÷ Time
What is the dimension of acceleration?
Velocity ÷ Time
Which is equal to
Length ÷ time^2
What is the dimension of time?
None
What is the dimension of mass?
None
What is the dimension of weight and force?
Mass X Acceleration
What is the SI unit for displacement?
Meters
What is the SI unit for distance?
Meters
What is the SI unit for speed?
ms^-1 or m/s
What is the SI unit for acceleration?
ms^-2 or m/s^2
