How and when does Newton's First Law apply to the launch of a rocket?
What changes could we make to a rocket to achieve a greater acceleration? How is this supported by Newton's Second law?
How does Newton's 3rd Law make it possible for a rocket to fly even fly in space?
When the rocket is on the launchpad and at rest, it will stay at rest until acted upon by an external force.
A lighter rocket would give a higher acceleration than a heavier rocket. This is supported by the second law (F=ma), acceleration is produced when a force acts on a mass. The bigger an object's mass that is accelerated, the larger the amount of force needed to accelerate the object.
The third law states for every action there is an equal and opposite reaction. This means the rocket is being pushed by the engine's thrust downwards, but causing the rocket to go upwards (flight).