Law of Inertia (Newton’s 1st Law) An object at rest remains at rest unless acted upon by a force. An object in motion remains in motion, and at a constant velocity, unless acted upon by a force. E.g. we have to overcome gravity to jump, or tackling someone in rugby http://www.youtube.com/watch?v =Rq2Xb3BQZyY

Question Consider a football player who is looking to head the ball into the net. What must be done to change the direction of the ball from across the goal to towards the goal?

A force must be applied greater than the inertia of the ball so its direction can be changed Consider what would happen if the ball was heavier? Or lighter?

F = MA (Newton’s 2nd Law) When a force is applied to a mass, the result is acceleration of that mass in the direction the force is applied. The greater the force applied to a mass the greater the acceleration http://www.youtube.com/watch?v= VieEzw14h_Y

In a golf context….. The golf ball has it’s own inertia and it needs to be acted upon by a force to move the ball. The force is created through the swinging of the club. Where the force is applied depends on the direction of the ball so keeping the club head on the plane means the ball will fly straight, not slice or pull.

What can act on the inertia of the ball to slow it down or take it off line? Wind Gravity Make up of the ground e.g. grass, sand, water trap Air resistance Remember F=MA so more force is created from a driver because of the club head and the speed it generates (acceleration)

Question Consider the situation of a serve in tennis, a kick in soccer, shot at goal in hockey or a pitch in softball How can we apply Newton’s Second law to produce a more powerful strike, throw or pitch?

The greater the initial input of force, the greater the acceleration of the object upon contact or release. The longer the lever the greater the force at the extremity, thus greater acceleration on the object on contact or release

Action/Reaction (Newtons 3rd Law) For every action there is an equal and opposite reaction. What are some examples of action-reaction in sport?

Examples Running High Jump Kicking a Ball Hitting a ball Punching in boxing Sprinting http://www.youtube.com/watch?v=FVX vPMV9cCI http://www.youtube.com/watch?v=By1 JQFxfLMM

In a golf context…… Every action has an equal or opposite reaction. So when I hit the golf ball the equal or opposite reaction is for the ball to fly through the air. You can see this happening in this video: http://www.youtube.com/watch?v= 2Y57pw_iWlk