LINEAR MOMENTUM AND IMPULSE EQUATIONS

   Linear Momentum Equation

   The linear momentum of a particle with mass ‘m’ moving with velocity ‘v’ is defined as product of mass and velocity .i.e:

      p = mv

    It is based on the law of conservation of momentum or on the momentum principle, which states that the net force acting on a fluid mass is equal to the change in momentum of flow per unit time in that direction. The force acting on a fluid mass ‘m’ is given by the Newton’s law of motion,

   F=m*a



  where a is the acceleration acting in the same direction as F.

    IMPLUSE FORCE AND EQUATIONS

    The impulse-momentum equation can be easily derived from kinematics and Newton's Second Law. This equation is very closely related to newton’s second law - in fact, it is often called the "Impulse-Momentum form of Newton's Second law.

   Eq(2) is known as momentum principle.
   Eq(2) can be written as :  F.dt=d(mv) .........Eq(3)

Here Eq(3) is known as the impulse-momentum equation and states that the impulse of a force F acting on a fluid of mass ‘m’ in a short interval of time dt which is called impulse force is equal to the change of momentum d(mv) in the direction of force.  

Fluid momentum: