Dynamics Flashcards
Newton’s First Law
An object continues in its state of rest of constant velocity in the absence of an external resultant force.
Newton’s Second Law
The rate of change of momentum of an object is directly proportional to the external resultant force acting on it.
The change in momentum takes place in the direction of the external resultant force.
Newton’s Third Law
When object A exerts a force on object B, then object B exerts a force of the same type that is equal in magnitude and opposite in direction on
object A.
Inertia
The property of a body associated to its mass which is a measure of the body’s resistance to change in its state of rest or uniform motion in a straight line.
Weight
The force acting on a mass due to a gravitational field.
Linear momentum
The linear momentum of a body is the product of its mass and its velocity.
Impulse
The product of average force F and the time of impact, change in t.
Impulse-Momentum Theorem
The impulse of a force acting on an object is equal to the change in the momentum of the object.
Principle of Conservation of Momentum
The Principle of Conservation of Linear Momentum states that the total momentum of a system of interacting bodies is constant provided no external resultant force acts on the system.
Elastic collision
The total momentum and total kinetic energy are the same before and after the collision. Relative speed of approach equals relative speed of separation.
(BUT total KE may not be conserved DURING the collision, only before and after)
Inelastic collision
The total kinetic energy for the objects after the collision is less than the total kinetic energy of objects before the collision.
The relative speed of approach of the objects is not equal to the relative speed of separation of the objects.
Perfectly inelastic collision
In a perfectly inelastic collision, both objects will have the same speed after the collision.
