Answer:
See Explanation
Explanation:
According to Newton's second law of motion, the acceleration of a body is proportional to the net external force that acts on the body.
A body accelerated when it is acted upon by an unbalanced net external force.
When the external forces acting on a body are balanced, the effect of each force is cancelled by the other hence the body is not accelerated according to Newton's second law.
I know that its not the second law. I'm almost positive its the first one. Please let me know if I'm wrong. This sentence makes no sense when you put it with the third law. So, the first law is my guess...