U4 - Mechanics Flashcards
When is an object in equilibrium?
When there is no resultant force acting upon the object and moments balance.
What is Newton’s First Law (Law of Inertia)?
Every body will continue at rest or with a CONSTANT VELOCITY unless acted upon by a resultant force
What is Newton’s Second Law?
The resultant force is proportional to the rate of change of momentum and acts in the same direction as the change in momentum.
Resultant force is proportional to mass and acceleration.
F = ma is a special case where mass is constant and cannot be used for a rocket where the fuel is being used up.
What is Newton’s third law of motion?
For every action, there is an equal and opposite reaction.
What must the forces in Newton’s third law be of?
They must be of the same type.
