Physics
Define "centre of mass"
The point where the entire mass of a body is considered concentrated
Define a "couple"
Two forces (with the same magnitude) which are parallel along different lines
Define "Torque"
The moment about the pivot point resulting from a couple
Define "Moment"
The force multiplied by the perpendicular distance from the line of action
What is the principle of moment
The sum of the anticlockwise moment = The sum of the clockwise moment (for an object in equilibrium)
State 2 conditions for an object to be on equilibrium
- The total resultant force must equal zero
- The total torque must equal zero
Define 'Drag'
A frictional force that opposes the motion of an object
Give 3 factors that affect Drag
- Velocity
- Surface Area
- Fluid density
- Surface friction
What two things is drag directly proportional to
- Cross-sectional area
- (Velocity)²
define "Friction"
The force that arises when two surfaces rub against each other
Define a "Newton"
The net force when a 1kg mass has an acceleration of 1ms‐²
Define 'Density'
The mass per unit of volume of an object
Define 'Normal Contact Force'
The force that arises when an object rests on another object
Define 'Weight'
The gravitational force acting on an object via its centre of mass
Define 'Tension'
The force within a stretched cable/rope