SMART HOLIDAY FORM 5

This question no need to copy or print.Write your answer in the test pad. Your answer must be send to your fizik's teacher after school break.Happy holiday.

   1.  Diagram 4.1 and Diagram 4.2 show two night market stalls which are fixed with two identical bulbs that are connected to two identical car batteries 12 V with different length of connecting wires. Both bulbs bright up with different brightness.   

       Based on the information and observation:

       (a) State one suitable inference. 

       (b) State one hypothesis that could be investigated

       (c) With the use of apparatus such as dry cells, constantan wire, and other 

             apparatus, describe an experiment to investigate the hypothesis stated in 4(b).

Momentum

Introduction of momentum

Momentum is defined as the product of mass and velocity.

Momentum,  p  = m x v                                                              

            m – mass (kg)

            v – velocity ( ms^-1)

SI Unit:  is kg ms^-1. It can also be written as N s (Newton second)

Momentum is a vector quantity. The direction of momentum follows the direction of the velocity.

Principle of conservation of momentum

In any collision or interaction between two or more objects in an isolated system, the total momentum before collision is equal to the total momentum after collision.

m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂

Three types of collisions 
1)   Elastic collision

      Both objects move separately after collision.

    - In an elastic collision, the kinetic energy is conserved. 

     

     Total Momentum Before collision = Total Momentum after collision

                                    m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂

2)  Inelastic collision

     Both objects move together after collision.

    

    Total Momentum Before collision = Total Momentum after collision

                                  m₁u₁ + m₂u₂ = (m₁ + m₂) v

 3) Explosion

    Both objects are initially stationary, and move in opposite directions after the explosion. 

   
  

  
 Total Momentum Before collision = Total Momentum after collision
                                       (at rest) 0 = m₁v₁ + m₂v₂
                                             m₁v₁ = - m₂v₂

   * (-ve sign means opposite direction)

Application of Conservation of Momentum in Explosion 

  1. Fire a pistol or rifle
  2. Launching a rocket
  3. Application in jet engine
  4. Fan boat

MOMENTUM SONG