MOMENTUM

MOMENTUM•Every moving object has momentum.•When an object moving in a straight line, it has linear momentum.•The momentum of lorry is bigger than the car, even they move at the same speed.

• Momentum of an object is defined as the product of its mass and its velocity

Momentum = Mass x Velocity

Formula of momentum;

mvp

velocityv

massm

momentump

•S.I unit : kg ms¯¹

@ N s•It is a vector quantity

p : the momentum of the objectm : the mass of the objectv : the velocity of the object

Where is the mass???Where is the velocity???

How to calculate the momentum of the trolley?

3 kg

3 m/s

•A car of mass 800 kg is moving at a velocity of 50 ms-1 . The momentum of the car is….

A lorry moves with velocity 55ms-1. Given that momentum of the lorry is 286000kgms-1. Find the mass of the lorry.

Exercise……..

The figure above shows two objects A and B of masses 3 kg and 2 kg respectively moving towards each other. Find the momentum of object A and object B.

A trolley of mass 1.5 kg moves with a velocity 4 ms-1 hits a wall and rebounds along the initial direction with a velocity 3 ms-1 .Calculate(i) The initial momentum (ii) The final momentum (iii) The change of momentum

A ball of mass 0.5 kg hits a wall with a velocity of 10 ms-1 and bounces back with a velocity of 5 ms-1. Calculate the change of momentum of the ball.

Which object has the least momentum?

1. Object A: m = 1 kg, v = 100 m/s2. Object B: m = 10 kg, v = 12 m/s3. Object C: m = 0.5 kg, v = 1000 m/s4. Object D: m = 100 kg, v = 2 m/s

A car moves 200m in 4s. Given that the mass of the toy car is 600kg. Find the momentum of the car.

If a lorry reduces its mass by two times but increase its velocity by two times, its momentum

A. decrease by two times

B. increase by two times

C. increase by four times

D. remain unchanged

MOMENTUM

Product of

the mass

and the

velocityVector quantity:• Has magnitude• Has direction

p = m x v

unit : kgms⁻¹