Akif drives a car from rest at a point E on a straight road. He drives with constant acceleration for 20 s, reaching a speed of 25 m/s. Then, he travels at a constant speed of 25 m/s for 120 s. Finally, he drives with constant deceleration and comes to rest at a point F. Sketch a speed-time graph to illustrate the motion of the car.
Ahmad rides a motorcycle from rest at point E, 10 s after Akif has left E. Ahmad rides with constant acceleration from rest and passes Akif at a point D which is 1500 m from E. When Ahmad passes Akif, Ahmad is still accelerating and Akif is moving at a constant speed. Find the time Ahmad takes to travel from E to D.