Newton's second law says acceleration is directly proportional to net external force and:

1. The second law is the quantitative statement behind the first. 2. The acceleration of a system is directly proportional to and in the same direction as the net external force acting on the system. 3. It is also inversely proportional to its mass. 4. That is why the same push accelerates a light cart more than a heavy one. _Source: OpenStax College Physics for AP(R) Courses 2e (CC BY 4.0), Ch 4 'Dynamics: Force and Newton's Laws of Motion', sections 4.1-4.8_