Question

According to 3rd law of motion when we push on an object . the object pushes back on us with an equal and opposite force.if the object is a massive truck parked along the road side , it will probably not move .a student justifies this by answering that the two opposite and equal force cancel each other comment on this logic and explain why the truck does not move.

Answer 1

student's justification is not correct . two equak and opposite forces cancel each other if they act on the same body . according to the third law of motion , action and reaction forces are equal and opposite when they act on different bodies . hence they can not cancel each other
when we push the massive truck , then the force applied on the truck os not sufficient to overcome the force of friction between the tyers of the truth and ground . hence the truck does notmove