Linear momentum, sometimes simply call as momentum is the product of mass of the object and its velocity in the given direction. Linear momentum is a vector quantity and its direction will be same as the velocity of the object.

It can be formulated as-

G ⃗ = mV ⃗

Fig. 7.1 shows the linear momentum of an object about a point O

Differentiation the above equation, we get-

(dG ⃗)/dx = m (dV ⃗)/dx

= m a ⃗

(dG ⃗)/dx = ∑▒□(F ⃗ )

Or,

∑▒□(F ⃗ ) = G ̇ ⃗

Where,

∑▒□(F ⃗ )= Resultant of forces. It can be calculated as-

Resultant Force,

∑▒□(F ⃗ )= ∑▒Fxi ̂ +∑▒Fyj ̂+ ∑▒Fzk ̂

= G ̇xi ̂ +G ̇yj ̂+ G ̇zk ̂

Or,

∑▒Fx = G ̇x

∑▒Fy= G ̇y

∑▒Fz= G ̇z

**Note:**

The S.I. unit of Linear Momentum is kg. m/s

**Links of Previous Main Topic:-**

- Introduction to statics
- Introduction to vector algebra
- Two dimensional force systems
- Introduction concept of equilibrium of rigid body
- Friction introduction
- Introduction about distributed forces
- Area moments of inertia in rectangular and polar coordinates
- Mass moment of inertia introduction
- Work done by force
- Kinematics of particles
- Position vector velocity and acceleration
- Plane kinematics of rigid bodies introduction
- Combined motion of translation and rotation
- Rectilinear motion in kinetics of particles
- Work and energy

**Links of Next Mechanical Engineering Topics:-**