How do Newtons Laws of Motion apply to rocket flight?
When a rocket is lifting off from the launch pad, it is because the thrust exceeds the force that is keeping the rocket in place (weight of the rocket and payload caused by Earth’s gravity). The thrust of the rocket engine is greater than the weight of the rocket and the net force accelerates the rocket away from the pad. This reflects Newton’s First Law of Motion, which states that an object at rest will stay at rest as long as no unbalanced force is applied. When a rocket is being launched, there are two forces acting on it. One is the weight of the rocket, the force generated by the gravitational attraction of Earth on the rocket. The second is thrust, the force that moves the rocket. In general, the heavier the rocket, the more thrust needed to get it off the ground. The amount of thrust is determined by the mass of rocket propellant that is combusted, creating exhaust, and the speed at which the exhaust is vented from the rocket. Newton’s Second Law of Motion comes into play here,
