Define moment of force
Moment of force = force x perpendicular distance
State 2 conditions needed for a rod to be In equilibrium
Net force = 0
Net moment = 0
State 3 factors that affect the magnitude of drag force acting on an object through air
The surface area of an object
The velocity of the object
Density of the air the object is falling through
Define couple
Two equal but opposite forces equal distances from a pivot on either side
define torque of a couple
One of the forces x perpendicular distance between the forces
Define the newton
The net force when 1kg mass accelerates 1ms^-2
The vertical upward force on a spaceship stays constant. Explain why the acceleration of the spaceship increases after lift off
The rocket will be losing weight as it uses fuel
