Newton Laws of Motion

Newton 1st Law
an object at rest will remain at rest
E.g: Book Resting on a table
an object in motion will continue in motion at
constant speed in a straight line in the absence
of a resultant force acting on it.
Terminal Velocity
For Falling Object,
when Weight = Air Resistance,
No Resultant Force --> No Acceleration
Falling at a constant velocity (Terminal Velocity)
Factors Affecting Terminal Velocity
The greater the mass, the greater the terminal velocity
Surface Area
The greater the surface area, the smaller the terminal velocity
Force that opposes motion
Advantages and Disadvantages
of Frictions
Ways to Reduce Friction
Newton 2nd Law
Newton’s second law of motion states that the
resultant force acting upon an object is equal to the
product of the mass and the acceleration of the
Fr = ma
Resultant of Parallel Forces
Resultant of NonParallel Forces
Scale Diagram to solve for forces
Use to solve
Resultant Forces
Use Parallelogram/Triangle Method
Resultant force must have double arrow head
Forces in Equilibrium ( No balanced forces)
Use closed triangle method
Things to include in diagram:
1. Scale (1 cm rep 100N)
2. Parallelogram/ Triangle Method
3. Answer must include: Magnitude of Force and direction (means angle to which force)
Newton 3rd Law
Newton’s third law of motion states that for every action there is an equal and opposite reaction
If object A exerts a force on object B, then B exerts an equal but opposite force on A
Newton’s third laws tells us 4 characteristics of forces:
1. Forces always occur in pair. Each pair is made of an action and reaction.
2. Action and reaction forces are equal in magnitude.
3. Action and reaction forces are opposite in direction.
4. Action and reaction forces act on different bodies.
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