Which of the Following is Wrong about “Action and Reaction pair”
Action and Reaction forces cannot cancel each other to have zero resultant because they act on two different bodies
When a horse pulls a cart, the force that helps the horse to move forward is the force exerted by
Horse applies force on earth at certain angle. In turn earth apply force on horse horizontal component of this force helps the horse and cart to move forward.
A car accelerates on a horizontal road due to the force exerted by
Friction force applied by road on the car act in the direction of the motion which is responsible to move the car.
If a fly collides with the wind shield of a fast moving bus which experiences an impact force with a larger magnitude :
From Newton's third law of motion both bus and fly will experience equal force in opposite direction.
In a general debate on topic “normal reaction and mg never form action and reaction pair” a number
of students took part :-
(I) Navneet said – Action and reaction forces should be of same nature
(II) Anand said – Action and reaction forces act on two different bodies here, normal reaction and mg both are acting on the block.
(III) Meenakshi said – Action and Reaction forces balance each other. So, normal reaction and mg should be action and reaction pair.
Mark correct option as your judgement
The correct option is:
(II) Anand is correct.
Explanation:
Action and reaction forces act on two different bodies, as per Newton's third law. Normal reaction and gravitational force (mg) both act on the same block, so they cannot form an action-reaction pair.
If action force is gravitational force, then reaction force :
Action and Reaction forces are of same nature.
Assertion (A): According to Newton’s third law of motion, action and reaction forces are equal in magnitude and opposite in direction.
Reason (R): Net force on a body due to action-reaction pair is always equal to zero.
Assertion (A) is true: Newton's third law states that action and reaction forces are always equal in \(magnitude\) and opposite in \(direction\).nReason (R) is false: Action and reaction forces act on *different* bodies, so they cannot cancel each other out to produce a net force of \(0\) on a *single* body. Therefore, (A) is true but (R) is false.
Assertion (A): When two particles interact, net force on either particle is zero.
Reason (R): Both experience action and reaction which are equal and opposite.
Assertion (A) is false: When two particles interact, they exert forces on each other. Unless these interaction forces are exactly balanced by other external forces, the net force on *either* particle will generally *not* be zero, causing them to accelerate. Only the net force on the *system* of two interacting particles is zero (if no external forces are present).
Reason (R) is true: According to Newton's third law, when two particles interact, they exert action and reaction forces on each other which are always equal in magnitude and opposite in direction. Given that (A) is false and (R) is true, and option 'A is false but R is true' is not explicitly provided, option (4)
'Both (A) and (R) are false' is selected as it correctly identifies (A) as false.
Assertion (A): A man standing at rest on ground. Force exerted by man on ground is equal to weight of man.
Reason (R): Earth attracts man by force \(mg\) hence by Newton’s third law, man also attracts earth by same force.
Assertion (A) is true: the man exerts a force equal to his weight on the ground. Reason (R) is true by Newton's third law of gravitation for action-reaction. However, Reason (R) explains gravitational forces, not the contact force on the ground, so it is not a correct explanation for (A).
Assertion (A): A block is hanging from spring. Spring force on block and gravitational force on block are not action and reaction pair.
Reason (R): Action and reaction force acts in opposite direction.
Action and reaction pairs act on different bodies. Both spring force and gravitational force act on the same block, so they are not an action-reaction pair. Both A and R are true statements, but R does not correctly explain A.