Question

scientific principles involved in any 10 common wealth games stating the benifit of the principle to the athlete

Answer 1

Discuss throw and hammer throw:
 
       The athlete rotates two or three times before throwing the hammer or discuss.  The high angular velocity of the athlete gives a high linear velocity (tangential) to the hammer or discuss.  The hammer is revolved around the person very quickly to give a high linear velocity to it.
 
     The discuss or hammer must be thrown at an angle a little less than 45° to the horizontal to attain the maximum horizontal range.

Pole vault:

    The athlete uses a long flexible pole to jump over a great height. He uses the spring like nature of the pole and bends it towards him, while going up in to the air.  The reaction or restoration force in the pole pushes him further upwards overcoming the weight (gravity) of the person.

     The athlete turns himself upside down vertically to increase the jump height by the amount equal to his own height.

Shotput :

    This is to be thrown in to the air at an angle a little less than 45° to the horizontal to get to the maximum range.  The release point could be some distance into the measured area.  I mean the hand could extend in air as much forward as possible.  That increases the range.

Javelin :

      It should be thrown at an angle 45° to the horizontal to attain the maximum range.

In games like badminton and table tennis, the shoes worn are important.  To avoid slipping on the surface, athletes dip their shoes in a sticky substance.

In table tennis, the athletes use side spin and top spin, The spin causes different pressures on two sides of the revolving ball.  The difference in air pressure near the ball causes swing in the ball.

In boat rowing team event all the team members should move their oars in a synchronized manner so to maximize the forward thrust on the boat.  The athletes push the water back with the oar and hence they move forward with the reaction force of the water on the oars.

In foot ball, the ball is hit on the side while shooting at the goal post. The ball gains spin side ways and travels in a parabolic curve and deceives the goal keeper or opponents.  Here the movement of the ball in a curve is due to the spin and the difference of air pressure on two sides of the ball.