A distance-time graph shows: from $0$ to $1$ h the car covers $40$ km, then from $1$ h to $2$ h the distance…
A distance-time graph shows: from $0$ to $1$ h the car covers $40$ km, then from $1$ h to $2$ h the distance reading does not change, then from $2$ h to $3$ h the distance increases by another $60$ km. During the second hour the car was:
Moving faster than before
Stationary
Moving in reverse
Decelerating but still moving
Solution
Distance does not change during the second hour, so the graph is horizontal: the car is stationary.