Learning Outcomes

Learning Outcomes • All are able to describe the forces acting on a sprinter. • All are able to complete an examination question to demonstrate knowledge and understanding. • Most are able to explain and apply Newton’s Three Laws to at least two named sports. • Some are able to analyse the theory of Newton’s Three Laws using their own examples.

Homework • Watch video clips on projectile motion on weebly and complete worksheet to demonstrate understanding. • Complete exam questions on forces and Newton’s Law • Prepare for activity – ‘there can be no sport without force’.

Starter Activity • Complete True and False activity to demonstrate knowledge gained last week and to introduce forces.

Forces acting on a sprinter

Air resistance Gravity Friction Equal and opposite Ground Reaction Force Action force of muscular contraction Forces acting on a sprinter

Mini plenary • Use your text book to find out 1. The three factors affecting friction 2. The three factors affecting air resistance

Newton’s Laws of Motion • http://www.youtube.com/watch?v=UVdqxYyFRKY&gl=GB&hl=en-GB&feature=related

A body will continue in a state of rest or uniform motion unless acted upon by an external force. A body has a reluctance to change in its state of motion. If a force acts on an object, it will accelerate in the direction of the force. If an object is given an initial velocity and there are no forces acting on it, the object will continue along its original path in a straight line. Newton’s First Law: Law of Inertia

The rate of change of momentum of a body is proportional to the force causing it and takes place in the direction in which the force was applied. In sport mass remains constant therefore mass equates to acceleration. The greater the force being exerted on an object, the faster the object moves. A big mass (tennis ball) is harder to accelerate than a smaller mass (table tennis ball). Newton’s Second Law: Law of acceleration

For every action there is an equal and opposite reaction For every force between two objects there is always an equal but oppositely directed force. The normal reaction force is the support force exerted upon an object which is in contact with another stable object. Newton’s Third Law – the Law of action and reaction Normal reaction force Weight

Application of the theory • Apply Newton’s three Laws of Motion to the following situations: • A high jumper at take off • A high diver performing a dive • A gymnast performing a vault • A football player taking a penalty Extension: come up with an example of your own to illustrate your understanding further

All are able to complete an examination question to demonstrate knowledge and understanding. • A sprinter uses her calf muscles to push on the blocks at the start of a run. Explain, using Newton’s laws, how this enables her to accelerate forwards out of the blocks. 3 marks

A sprinter uses her calf muscles to push on the blocks at the start of a run. Explain, using Newton’s laws, how this enables her to accelerate forwards out of the blocks. 3 marks • Newton’s 1st law - Sprinter remains in a set position on the blocks until a force causes him to change his position • Newton’s 2nd law of motion - if a force is exerted, then this produces an acceleration in the same direction as the force (forwards). – sprinter pushes • Newton’s 3rd law of motion - action and reaction are equal and opposite in direction. • • When the sprinter pushes down and back on the ground. • • The ground pushes up and forward on her.

Plenary activity • Return to your starter activity and check the work on forces to see what progress you have made. • Write either • a sentence, • four words or • draw a diagram to illustrate your understanding of Newton’s 3 Laws.

Learning Outcomes