1.6 - Newton’s Laws of Motion

Newton’s first law

body remains at rest or state of motion with constant velocity unless acted upon by resultant force

Newton’s second law

acceleration of object directly proportional to resultant force acting upon it and occurs in resultant force direction

Newton’s third law

if body A exerts force on body B, then body B exerts equal but opposite force on body A

Newtons equation

F = ma

Why does alcohol affect stopping time?

increases reaction time so thinking distance greater

Why does rain affect stopping time?

wet conditions reduce friction increasing breaking distance

How to work out breaking distance

thinking time + stopping time

Three properties linked to newtons law

equal in magnitude, opposite directions, act on different bodies

F = ma equation in an elevator - stationary

R = ma

F = ma equation in an elevator - accelerating up

R = mg + ma

F = ma equation in an elevator - accelerating down

R = mg - ma

F = ma equation in an elevator - freefall

R = 0