Question

State with reasons, it is possible or impossible for an object to have acceleration opposite to the direction of motion.

Answer 1

We know that in physics, motion is defined as the change in position of an object with respect to initial position and time. We also know that when an object is in motion, it can be expressed or described in terms of a few physical parameters, like displacement, velocity, acceleration, distance and speed.

Complete answer:
We know that acceleration is defined as the rate at which the velocity of the moving object changes with time. Thus, clearly, acceleration depends on motion of the object.
Consider Newton's second law of motion, which states that the force $F$ applied to move a constant mass $m$ is directly proportional to the acceleration $a$ of the object.
$F\propto a$
$\implies F=ma$
Thus, from the above equation, we can say that the direction of force , which in turn leads to motion gives the direction of acceleration of the object.
Let us consider the following examples:
A ball thrown down from a height, experiences a gravitational pull called the acceleration due to gravity in the downward direction.
Here, both the direction of the motion of the ball and the acceleration of the ball is in the same direction i.e. downwards.
Now, consider the ball being thrown upwards into the air, then acceleration due to gravity acting on the ball, acts in the downward direction.
Here, the direction of the motion of the ball and the acceleration of the ball are in the opposite directions.
Thus, we can conclude that it is possible to have cases, where the direction of motion and acceleration are opposite to each other.

Note:
Since acceleration is a vector quantity, it has both direction and magnitude. Then, we can say that the value of acceleration can be both positive or negative. We know that force can either be a push or pull, then accordingly, the direction of force and acceleration can vary.