Mechanics

what is a moment

the turning effect of a force

what is the principle of moments

for an object to be in equilibrium the sum of the clockwise moments must equal the sum of the anticlockwise moments

what is the centre of mass

the point through which a single force on the body has no turning effect and where the weight of the body is considered to act.

what is a couple

a pair of equal and opposite forces acting on the same body along the same line

what is a torque

the total moment of a couple

for an object to be stable what needs to happen

the weight must be acting within the object

what is one km/h equal to

0.28m/s

what is one m/s equal to

3.6 m/s

what is an elastic collision

no kinetic energy is lost in the collision

what is an inelastic collision

the objects have less kinetic energy after collision than before

why does an object balance about its centre of mass

mass is equally distributed on both sides therefore acw moments = cw moments