The sum of forces acting on a particle of constant mass is equal to the product of the mass of the particle and its acceleration; 3. The forces exerted by two particles on each other are equal in magnitude and opposite in direction.
Dynamics and Vibrations - Forces and Momentswww.brown.edu › Engineering › Courses › Notes › Forces
The sum of the forces is equal to the mass times the acceleration. The 2nd law tells us that if the object or system is motionless, the acceleration is equal to zero.
