Form 4 - 2.2 Analysing Motion Graphs

 

 

Exercise 1 :

                              

Answers :

a)  Velocity = Gradient of graph = 15/3 = 5 m s-1

b)  Time = 10 – 3 = 7 s

c)   t = 15 s

d)  i)  Average speed = Distance/time = (15+15)/15 = 2 m s-1

     ii) Average velocity = Displacement/time = 0/15 = 0 m s-1

Exercise 2 : 

Answers :

a)   a = Gradient =(0-12)/(13-10) = -4  m s-2

      deceleration = 4 m s-2

b)  Displacement = area under the graph

                              = ½  x 12 x (4 + 13)

                              = 102 m northwards

c)  Time   = (20 – 15) = 5 s

d)  Area of triangle = ½ x 10 x 5 = 25 m

      Final displacement = 102 – 25 = 77 m towards the north.

e)   Average velocity = Final displacement / time

                               = 77 m / 20 s

                               = 3.85 m s -1