Hello
The bullet is moving by uniformly accelerated motion.
The initial velocity is

, the final velocity is

, and the total time of the motion is

, so the acceleration is given by
where the negative sign means that is a deceleration.
Therefore we can calculate the total distance covered by the bullet in its motion using

So, the bullet penetrates the sandbag 1.8 meters.
Using the given equation:
di = 20.0 * 10.0 / 20.0 - 10.0
di = 200/10
di = 20.0 cm
The answer is A.
The upward force the table exerts on the ground!
Equal and opposite forces.