Dynamics and Kinetics
Sir Isaac Newton (1642-1727)
Newton's First Law states: "All objects will remain in a state of rest or continue to move with a constant velocity unless acted upon by an unbalanced force. Also known as the Law of Inertia."
Newton's Second Law states: "The acceleration of an object depends inversely on its mass and directly on the unbalanced force applied to it."
Newton's Third Law states: "For every action force, there is an equal and opposite reaction force."
In badminton, while the object (shuttlecock) is in motion, it will continue to travel with a constant velocity, but because of air resistance it creates a projectile motion and it will decelerate. The unbalanced force acting upon the shuttlecock is the racket which hits it in the opposite direction. This is how it relates to Newton's First Law.
Newton's Second Law states: "The acceleration of an object depends inversely on its mass and directly on the unbalanced force applied to it."
Newton's Third Law states: "For every action force, there is an equal and opposite reaction force."
In badminton, while the object (shuttlecock) is in motion, it will continue to travel with a constant velocity, but because of air resistance it creates a projectile motion and it will decelerate. The unbalanced force acting upon the shuttlecock is the racket which hits it in the opposite direction. This is how it relates to Newton's First Law.
A badminton shuttlecock generally weighs approximately 5 g. Assume that a shuttlecock weighs 5 g and one that weighs 25 g. How would an athlete's performance differ if they were to use shuttlecocks at different weights? If an equal force is applied for both shuttlecocks, the lighter one will attain a greater velocity and a farther distance while the heavier one will achieve the opposite. The reason being is because the heavier shuttlecock has more inertia due to its mass. For the heavier shuttlecock to create an equal velocity as the lighter one, a greater force must be applied. Hence, the acceleration of an object is clearly related to the equation a= Fnet/m or Fnet = ma, where 'Fnet' is the net force, 'm' is the mass, and 'a' is the acceleration. If the mass of an object is greater, more force is needed for an increase in acceleration and vice versa. Consider this:
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Case 1 A badminton player hits the shuttlecock and exerts a force of 0.25 N. If the shuttlecock weighs 5.0 g, what is the acceleration? F=ma F=0.25 N m=0.005 kg a= ? 0.25=(0.005)(a) a=0.25/0.005 a=50.m/s^2 ∴the acceleration of the shuttlecock is 50.m/s^2 | Case 2 A badminton player hits the shuttlecock and exerts a force of 0.25 N. If the shuttlecock weighs 25 g , what is the acceleration? F=ma F=0.25 N m=0.025 kg a= ? 0.25=(0.02)(a) a=0.25/0.025 a=10.m/s^2 ∴the acceleration of the shuttlecock is 10.m/s^2 |
When a shuttle is hit from your racquet, you may feel a slight vibration at impact. This in fact is a proof of Newton's third law: For every action force, there is an equal and opposite reaction force. The action force is the racquet swinging in a direction and the reaction force is the shuttlecock pushing back in the opposite direction (Fig. 2). |