1. NEWTON'S SECOND LAW

2. OBJECTIVES  Students will be able to explain Newton's second law of motion.  They will be able to derive the formula for calculating force with the help of Newton's second law of motion.

3. NEWTON'S SECOND LAW OF MOTION  This law states that the rate of change of Momentum is directly proportional to the applied force & it takes place in the same direction in which the force acts. For understanding this law we should be very clear about Momentum. It is the product Of mass and velocity.The force required to stop a moving body depends upon its mass & velocity.

4.  Now suppose a body of mass ' m ' is moving with an initial velocity Of ' Vi ' and changes its velocity to ' Vf ' after time ' t '.Then it's initial momentum will be mVi and final momentum will be ' mVf ' ( mass X velocity ).Change of momentum in time ' t' will be ( mVf - mVi ). So rate of change of momentum is ( mVf- mVi ) / t which is directly proportional to the applied to Force acc. to Newton's second law.

5. So F =m ( Vf - Vi )/t ( Take ' m ' common ). Now Vf - Vi / t = acceleration ' a ' (rate of change of velocity ) Therefore F = ma ( Product of mass and acceleration ) In this way with the help of this formula we can calculate the amount of applied Force.