Momentum

📚 Key Concepts

🔹 Definition of Momentum

Momentum is the product of the mass and velocity of an object.

Formula: p = mv
Where:
* p = momentum
* m = mass
* v = velocity

Unit: kg⋅m/s

Properties:

• Momentum is a vector quantity
• Direction is the same as that of velocity
• Depends on both mass and velocity

🔹 Understanding Momentum

Key Points:

• More massive objects have greater momentum at the same velocity
• Faster objects have greater momentum at the same mass
• Momentum is zero when an object is at rest (v = 0)

Real-Life Examples:

• A loaded truck has more momentum than an empty truck at the same speed
• A fast-moving bullet has high momentum despite small mass
• A slow-moving elephant has huge momentum due to large mass
• A cricket ball and tennis ball at same speed — cricket ball has more momentum

🔹 Momentum in Daily Life

Sports Applications:

• Football: Players with more mass are harder to tackle
• Cricket: Fast bowlers deliver high momentum balls
• Athletics: Heavy athletes need more force to stop

Transportation:

• Heavier vehicles are harder to stop
• Braking distance depends on momentum of vehicle
• Vehicle safety designs consider momentum (airbags, crumple zones)

🔹 Change in Momentum

When velocity changes:

• Change in momentum = m(v – u) = m × change in velocity
• Greater change in momentum requires greater force
• More time taken means less force required (impulse)

Applications:

• Airbags: Increase time and reduce force in collisions
• Crumple zones: Increase stopping time to reduce injury
• Sports equipment: Designed to manage momentum changes safely