Standard Grade Knowledge & Understanding Skills & Techniques - Mechanical Principles Balance Force Resistance Friction

Learning Outcomes By the end of this lesson you will; Understand the role balance plays in an activity Understand how forces affect sporting activities. Understand how resistance affects performance.

Balance Balance – The ability to remain balanced depends on 2 things: If your base of support is large your balance will be more stable Balance – The ability to remain balanced depends on 2 things: A) Base of Support B) Centre of Gravity Balance is the ability to retain the centre of gravity over your base of support. If your base of support is small, it is harder to maintain your balance

Balance STATIC Static balances such as headstand in gymnastics require you to hold a balance Dynamic balances require you to maintain balance under constantly changing conditions. When skiing you constantly adjust your dynamic balance as you travel over changing terrain in order to remain balance DYNAMIC

Centre of Gravity Centre of Gravity – is your point of balance. When standing upright it is near your belly button If your centre of gravity is low you will balance more easily If you move your centre of gravity outside your base of support, you will lose your balance.

Good balance is very important to be successful in lots of activities: A large base allows the golfer to be balanced in preparation for his swing A low centre of gravity allows a volleyball player to remain balanced when performing a dig Having his centre of gravity over his base allows the footballer to be balanced during his shooting action

Force Force is energy produced when our muscles contract. This energy allows us to move our body or parts of our body. When performing different skills and techniques different forces are applied and resisted. For every action there is an equal and opposite reaction. (Newtons 3rd law)

Force In many activities you use force to overcome resistance. the sprinter uses the staring blocks to push back against and travel forwards. For the activities below write down, the direction of the force and the direction of the movement.

Resistance Resistance is a force that slows down or opposes another force. Resistance can be an advantage or a disadvantage.

DISADVANTAGES OF RESISTANCE CYCLING Wind can act as a resistance. This can be overcome. Cyclists wear tight lycra clothing, which helps reduce air resistance, and lets them cycle faster A specially designed helmet and curved body position also helps to reduce air resistance SWIMMING Water acts as resistance but this can be reduced through tight clothing, wearing a cap or even shaving body hair Streamlining