Newton’s Laws: Newton’s Laws Of Motion Flashcards
What is the first Law of Motion
If R.F is zero, all forces are balanced
If the forces on an object are balanced, the object will continue to do what it was already doing.
Stationary will remain stationary
Moving, continues to move at the same speed in the same direction
Exam definition of Newton’s First Law of Motion
A body will remain at rest or continue to move with a constant velocity unless acted upon by a force
What is Newton’s second law of Motion
If R.F is not zero, forces said to be unbalanced
Speed and direction may change
Speed increases or decreases
Resultant Force is proportional to the rate of change of momentum
They occur in the same direction of that force
What does rate of change of momentum also refer to
Mass x Acceleration
change in momentum/ time
mass x change in velocity/ time
mass(v-u)/time
Exam definition of newtons second Law of Motion
Resultant force acting on an object is directly proportional to the rate of change of momentum and occurs in the same direction of the force
What equation can be derived from Newton’s second law
F=ma
Exam definition of Newton’s Third Law of Motion
When one body exerts a force on another, the other body exerts an equal in magnitude and opposite in direction force on the first body
When is Newton’s Third Law applicable
When the forces are a pair, the same type of force
When they are equal and opposite
When they act on two different objects
Examples of Newton’s Third Law
Gravity- force due to gravity on book equal and opposite to force due to gravity on from the ground
Contact/ reaction force
What is momentum?
A measure of how difficult it is to stop a moving object
Exam definition of net force on a body
Equal to rate of change of its momentum
How to calculate change in momentum?
p after - p before
+mv- -mv
What is impulse?
Ft
Force x time for which the force acts
What is the equation for impulse?
Impulse= force x time
What is Newton’s second law of Motion?
The resultant force acting on an object is directly proportional to the rate of change of momentum
The rf and change in p occur in the same direction of that force
