Wednesday, March 16, 2011

Physics Form 4: Chapter 2 -Graph of Motion

Displacement-Time Graph:

  • Gradient of the graph is equal to velocity
  • Gradient = 0 , velocity = 0.
  • Gradient is negative and constant, hence velocity is uniform and in opposite direction.
  • Gradient is increasing, hence velocity is increasing.

 Velocity-Time Graph:

  •  The gradient of the velocity-time graph gives acceleration.
  • Gradient = 0, hence velocity is constant but acceleration = 0.
  • The area below the velocity-time graph gives a value of the object's displacement.  

Click on the diagram below to play!


    Anonymous said...

    Cikgu Wong, can you help me to solve this question.

    In emergency stop, a driver applies the breaks in a car travelling at 24 ms-1. The car stops after travelling 19.2m while braking. Calculate the average acceleration of the car during braking?

    cikgu wong said...

    Initial velocity, u = 24
    Final velocity, v = 0
    Total distance, s = 19.2

    Use V2= U2 + 2as formula
    0 = 576 + 2a(19.2)
    a = -576/19.2 = 30 ms-2

    Anonymous said...

    Thank you cikgu wong

    siti aisyah said...

    im always confuse when i want to use the formula..which formula shouls i use .can you help me and teach me how to use formula based on the question

    Manisha Majid said...

    cikgu wong , why don't you just use this formula , v-u/t , for the first question in the comments ?

    Anonymous said...

    Manisha, it is because, there is no time required in the question. so you cannot use the formula v-u/t.