Difference between Second law and Third law of motion
Second law of motion
1.) Newton’s second law illustrates the necessity of change of momentum to change the inertia of object.
2.) Newton second law states as ‘rate of change of momentum is directly proportional to the impressed force and the change in momentum is takes towards the direction of applied force.’
3.) This law indicates that the momentum of object should be change to make an impact on object.
4.) The formula for Newton’s second law of motion can be given as,
∴ F =m a
Where ‘m’ is mass of object and ‘a’ is the acceleration of object.
5.) Eg. To find the force exerted on wall by a ball of mass 50 g thrown with acceleration of 10 m/s2 will be,
∴ F = 0.05 × 10 = 0.5 N
Third law of motion
1.) Newton’s third law illustrates the action and reaction pairs formed between interacting bodies.
2.) Newton’s third law states that ‘for every action force, there is equal, opposite and instantaneous reaction force.’
3.) Magnitude of action and reaction forces is equal but the direction is opposite.
4.) During the reaction, the direction of velocity of object is always gets reversed so as to reverse the direction of force too.
6.) This law is useful to understand concepts like projection of satellite, recoil of rifle etc.