Question

Give two situations where net force acting $0$ on $2$ bodies is zero.

Answer 1

Hint: An entity that is initially at rest and has no net forces acting on it will remain at rest. If it's going, it'll keep moving in a straight line at a steady pace. Forces are "pushes" or "pulls" on an object, and they are vector quantities, including velocity and acceleration.

Complete answer:
Let's start with a box with holders on both sides. Begin pulling with the string on both sides with equal force from either hand. The box can never turn when it is in equilibrium, which means it meets the first condition of equilibrium. $F=0$, in other words.

Now, on both sides, transfer the holders to the top and bottom corners, respectively. Begin pulling from each holder now. And if the first condition of equilibrium has not been met, the box now has a propensity to rotate. But that's the first case in point. Second, make a metre rule that is approximately 1 metre long. Place your index fingers in the exact middle of both sides of the metre law.

And then begin clicking. There will never be any torque generated by the body. However, transfer your fingers to the metre rule's ends. The body will now have a proclivity to spin. In reality, a condition where the net force is equal to zero is unrealistic. When the body's net force is equal to zero, it can't be accelerated.

Newton's second law of motion explains this. Since $F = ma$, here $F$ stands for force, $m$ for mass, and $a$ for acceleration.However, since mass cannot be zero, acceleration must also be zero. Acceleration is the process of increasing or decreasing your rpm. When there isn't any acceleration, the body begins to travel at its previous pace. This speed can be anywhere from $0$ to infinity. The body is at rest while moving at zero speed. As a result, it does not always imply that the object should be at rest.

Note: A body is assumed to be in the translational equilibrium if the net force acting on it is zero. In this case, the body's centre of mass either stays stationary or travels rectilinearly at a constant velocity.