Answer:
Its acceleration is certainly negative.
Step-by-step explanation:
- When an object moving in a straight line decelerates then its velocity certainly decreases.
- Its acceleration is certainly negative.
- As we know that acceleration is the rate of change in velocity and the object is decelerating i.e. its velocity is reducing with time.

where:
are final and initial velocities of the object
are final and initial time of observation.
- Its SI unit is
