Behind every action in cricket, there is a scientific principle involved. From a bowler bowling a delivery, to the fielder stopping the ball, Science is applied everywhere. In this section, we will learn about how science is applied in cricket.
- Application of Newton’s Laws of Motion in Cricket
- Why does the shot feels so nice when hit from middle of the bat?
- Swing Bowling – Convectional Swing
Application of Newton’s Laws of Motion in Cricket –
1st Law of Motion – A body in motion or at rest will remain in motion or rest unless an external unbalanced force is applied on the body.
A ball remains at rest until the bowler applies force on it. Similarly, when a batsman hits the ball, it continues to travel in the direction of the hit. It stops only when fielders apply force or by frictional force due to ground.
2nd Law of Motion – Rate of change of momentum of particle is directly proportional to force applied.
While catching a ball, the fielder draws his hands backward. This allows a longer time for his hands to stop the ball. Due to more time taken, rate of change of momentum of ball is decreased. Hence, small force is exerted on the hands and the players do not get hurt.
3rd Law of Motion – Every action has equal and opposite reaction.
While bowling, the bowlers apply a force to the ball. At the same time, the ball applies an equal force on the bowler. Due to this force by the ball, the bowlers feel strain in their muscles. Since, the fast bowlers apply a much greater force to the ball, they are more prone to injuries than spinners.
Why does the shot feels so nice when hit from middle of the bat?
When a batter hits the ball from middle of the bat, he requires little force to hit the ball farther and the shot feels so nice. This “middle of the bat” is called a sweet spot, and scientifically it is called vibration node. When the ball hits the bat, it causes the bat to vibrate. These vibrations cause the bat handle to jerk forward and backward. Due to these jerks, the shot feels unpleasant.
As the impact of the ball moves closer to the vibration node, the vibrations get weaker. At the vibration node or the sweet spot, there are no vibrations at all. So when the ball hits this node, minimum effort is needed to strike the ball and the shot feels nice.
Swing Bowling – Convectional Swing
Swing Bowling refers to the change in the direction of the ball mid air, either towards the batsman or away from the batsman. Swing bowling is of two types: conventional swing and reverse swing. Here we will learn about science behind the Convectional Swing.
There are five factors that determine the swing of the ball –
- Wear and tear of the ball ( Shine of the ball )
- Seam of the ball
- Speed at which the ball travels
- The way the bowl is bowled.
- The wind
The bowlers and fielders keep rubbing and polishing one side of the ball. This is done to maintain the shine of the ball on one side and keep the other side rough. This is the key to the swing of the ball.
Fast bowlers swing the ball by keeping the seam inclined at an angle of about 20 degrees to the direction where they need to swing, in such a way that about 3/4 of the front of the ball is shined.
If the seam is kept towards the batsman while bowling to a right handed batsman, you will get an In-swinger as the wind will push the ball into the batsmen. Similarly If the seam is kept away from the batsman while bowling to a right handed batsman, you will get an out-swinger as the wind will push the ball away from the batsman.
When the air moves around the shined part of the ball, it is said to be in laminar state and the airflow is smooth and regular. When the air moves around the rough part of the ball, it becomes turbulent as is has to flow past the seam. Turbulent air is at a lower pressure than smooth flowing air.
When the bowler delivers the ball, it moves through the air and a thin layer of air is formed around the surface of the ball. This surface is called the boundary layer. It has two states – Laminar state and turbulent state.
Now there is a pressure difference between the top of the ball and the bottom of the ball. Hence, due to a side force the ball swings in the direction in which the seam is pointing.