# Impulse and Momentum

**Impulse and Momentum**

**Defining Impulse and Momentum**

**Momentum**is a vector quantity and is described as the mass of an object multiplied by its velocity.**Impulse**is the product of the force applied to an object and the time during which it is applied.

**Impulse-Momentum Theorem**

- The
**Impulse-Momentum Theorem**states that the change in momentum of an object equals the impulse exerted on it. - In equation form, it is represented as: Ft = Δ(mv), where F is the force applied, t is the time, m is the mass of the object, and v is its velocity.
- If a net force is applied to an object, it will experience a change in momentum.

**Impulse and Real-World Situations**

- The concept of impulse can be applied in real-life situations. For example, when you catch a cricket ball, if you move your hand backwards on catching, you increase the time of contact which decreases the rate of change of momentum, leading to a smaller force on your hands.
- This concept is also used in safety technologies such as airbags and helmets, where they increase the time of impact, reducing the force experienced.

**Conservation of Momentum**

- The principle of
**conservation of momentum**states that the total momentum of a closed system is constant if no external forces act upon it. - This principle is applicable for all types of collisions – elastic, inelastic and perfectly inelastic.

**Momentum during Collisions**

- In
**elastic collisions**, both momentum and kinetic energy are conserved, meaning the total momentum and kinetic energy before the impact is the same as after the impact. - In
**inelastic collisions**, only momentum is conserved, and some of the kinetic energy is lost to other forms such as sound, heat or deformation of the objects. - In
**perfectly inelastic collisions**, the two objects stick together and move as one after the impact, but the momentum remains conserved.

**Momentum, Impulse and Forces**

- The concepts of impulse and momentum are crucial in understanding how forces can affect the motion of an object.
- They allow us to calculate the forces involved in a collision or explosion and predict an object’s motion post an impact or force application.