(a) Distance travelled by car in the 4 second
In the given graph
56 full squares and 12 half squares come under the area slope for the time of 4 seconds.
Total number of squares = 56+(12/2)

=62 squares
On the time axis, 5 squares = 2 s.
∴ 1 square=2/5s
On the speed axis, 3 squares = 2 ms⁻¹.
∴ 1 square=2/3 ms⁻¹
∴ Area of 1 square = 2/5×2/3

=4/15 m
∴ Area of 62 squares = 4/15×62
=248/15

=16.53 m
Therefore, a car travels 16.53 m in the first 4 seconds.

(b) From point A to B, the graph represents uniform motion.