Yes, it is possible. Acceleration is the rate of change of velocity, and velocity is a vector quantity with both magnitude and direction. An object moving vertically downward is decelerating in the upward direction, so its acceleration is negative. The magnitude of the acceleration of an object in free fall is equal to the value of gravity (g), but its acceleration can be less than g if there is an opposing force acting on it. For example, if an object is moving through a fluid (such as air or water), the fluid will exert a drag force on the object, which will oppose the force of gravity and reduce the magnitude of the acceleration. Another example is an object thrown vertically upward, which will accelerate downward at a rate less than g due to the air resistance.