Answer:
Zero
Step-by-step explanation:
Impulse is defined as the change in momentum.
Impulse is also defined as the product of force and the time duration of application of the force.
In the given problem, since there is no motion in the vertical direction, therefore the velocity of the box along the vertical direction is zero. So, momentum of the box along the vertical is also zero.
Hence the change is momentum is also zero along vertical direction.
Thus the impulse delivered by the box is zero.