Mathematics for IGCSE & O level - Graphs In Practical Situations (Section 1 - No. 3)
In the travel graph, what is happening in the segment labeled E to F? 
The truck is accelerating.
The truck is traveling at constant speed.
The truck is decelerating.
The truck is stationary.
Paliwanag
E to F is a downward sloping segment on the graph. This indicates deceleration.