Answer:
The acceleration of the crate is 
Explanation:
Recall the formula that relates force,mass and acceleration from newton's second law;

Then in our case, we know the force applied and we know the mass of the crate, so we can solve for the acceleration as shown below:

Answer:
first law: an object remains in uniform motion except an external force has acted upon it eg a ball in stable motion doesn't move until one moves or kicks it
second law:the body acted upon by an external force gains a momentum which is directly proportional to the applied force and acts in the direction of the force
third law: to every action there is an equal and opposite reaction eg if u push someone the person moves backward away from you and not towards you
This is true. Hope this helped:)