The distance covered by the blue car from one horizontal white strip to another, which is measured by scale is 1.2 cm.
It is given that 1 cm is equivalent to 100 m.
Therefore, 1.2 cm is equivalent to 120 m.
Distance travelled by car = 120 m
Time taken to cover this distance = Time interval between the two photographs = 10 s
Speed = distance/time = 120/10 = 12 m/sec