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
