# Give the quantitative expression of force.

Force can be calculated from Newton’s second law of motion which gives that force is the product of mass and acceleration.

• Newton’s second law states that the rate of change of momentum of a body is directly proportional to the force applied, and this change in momentum takes place in the direction of the applied force.
• Newton’s first law gives the law of inertia and the third law the action & reaction law.
• The Law of conservation of momentum states that initial momentum is equal to final momentum.
• F= ma