PHYSICS - dynamics

weight

W = mg

newton’s first law

• forces are balanced

• resultant force acting on object 0, forces acting on the object are balanced (at rest or uniform motion)

inertia

• greater mass, higher inertia

• dependent on mass

• harder to slow down, stop, start moving, change direction

newton’s second law

• resultant force on object not 0, forces are unbalanced

• resultant force acts on an object of a constant mass, it will accelerate in the direction of resultant force.

resultant force

F = ma

newton’s third law

• body A exerts a force Fab on body B, body B will exert an equal force of force Fba on body A.

• known as action reaction pair, equal in magnitude, act in opp direction

objects falling with air resistance

• when air resistance acting on object = weight, object starts to travel at a constant speed known as terminal velocity. Object has 0 acceleration