Unit 1.1:Scalars,Vectors & Moments Flashcards
What is a scalar quantity?
A quantity which can be described fully by giving only its magnitude.
State 3 scalar quantities
Speed
Distance
Mass
Energy
Power
Temperature
What is a vector quantity?
A vector quantity has magnitude and direction
State 3 vector quantities
Velocity
Acceleration
Force
Displacement
Weight
Momentum
What is Displacement?
Displacement is the distance moved in a straight line, in a given direction, from the starting point.
What is a resultant vector?
A resultant vector arises from adding vectors together
What does resolving a vector mean
It means splitting a vector into two mutually perpendicular components that add up to the original vector; these can be added ‘tip to toe’
State the equation used to calculate a moment and the units used
moment=force x distance
Units:Newton meters (Nm)
What is a moment defined as
The product of force and the perpendicular distance between the line of action and the pivot
What are the 2 conditions needed for equilibrium?
- The resultant force is zero
- The net moment is zero
State the principle of moments
If an object is in equilibrium, the net moments about any pivot is equal to zero.
Define ‘Center of gravity’
It is a point which all the weight of an object is considered to act
Define density
The measure of how concentrated the mass is per unit volume
State the equation and the units for density
p=m/v
Units:kgm-3
