Question

A car is traveling on a straight road and is decelerating. Does the car's acceleration necessarily have a negative value?

Answer 1

Deceleration:

1. When the speed of a body is reduced, it is said to be in deceleration.
2. It is nothing but the opposite of acceleration.

The negative value of car acceleration:

1. The velocity of the body decreases with time if it is decelerating.
2. Deceleration is the exact opposite of acceleration.
3. It always acts in the direction opposite to that of velocity.

So yes, if a car is traveling on a straight road and is decelerating, then it is necessary that the car's acceleration has a negative value.