Ball speeds and the fastest man explained!

Wimbledon 2015: fastest serve 235 kmph. 

Fastest cricket ball 161 kmph 

Fastest badminton smash 493 kmph 

U Bolt 37 kmph. 100m/9.58s

So, how do these players create such high speeds?

What is actually going on?

Let's examine racquet sports first. Tennis & Badminton.

The ball/shuttle is more or less stationary at start. And then it reaches speeds of 235 to 493 kmph!

For any object to change speed, it needs a source of power. And in sports, the only sources of power are the player and the racquet/equipment.

The power to get the ball/shuttle to move at such high speeds is generated by a combination of the following:

1. Body movement: If the ball/shuttle is too close to or too far from your body, you cannot generate enough power as you miss out the power that can be generated by a full swing. Also, the power is not only from the arms. The swivelling of the hips & feet movement in tennis or the alignment & rotation of the rest of the body in badminton adds to the power.

2. Arm movement: The arm has to move in line with the direction of the shot and hit the ball/shuttle in the right direction so as not to waste any power.

3. Racquets: Lower string tension and larger head size improves the power. In tennis, where there are different racquet sizes, smaller head sizes improve control.

4. Timing: Hitting the ball/shuttle ahead of the body and with the racquet face as perpendicular as possible to the final trajectory of the ball increases power.

Let's take cricket next.

How does fast bowlers bowl at 150-160 kmph?

1. Run-up: This creates the basic momentum required for bowling fast.

2. Bowling action: A smooth bowling action reduces wastage of energy and maximises pace. The movement of the front arm is as important as the bowling arm. A combination of the shoulder/arm strength as well as movement of the body creates pace.

3. Wrist action: The wrist is snapped at the time of release to add further pace.

How does Usain Bolt run so fast?

1. Take-off: Bolt has an explosive strength that is much higher than his competitors. So, he gets greater lift each time his foot hits the ground.

2. Stride length: At 6'5", he is not only taller but his strides are much longer. In his world-record setting run in 2009, he took 41 steps while his closest competitors took 44. (Read full article here)

3. Air-drag: Funnily, the air resistance should be slowing him down as he runs upright - unlike other athletes. But like the Bumblebee (that is not supposed to fly as per the known laws of physics), he does not seem to be aware of the laws of physics and goes ahead and runs faster than anyone else anyway!

How fast can you run? :)