An object is moving in the positive x-direction. Select all true statements considering its 1 dimensional motion.
a) If it is increasing its speed, its acceleration is in the positive x-direction.
b) If it is decreasing its speed, its acceleration is in the negative x-direction.
c) If it is not accelerating, it will move at a constant rate.
d) If it is increasing its speed, its acceleration must be constant.
e) If its acceleration is non-zero, it will move forward by equal amounts over equal time intervals.
f) It can be slowing down and have an acceleration in the positive x-direction.