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 for 03.03.15 Complete exam questions on forces and Newton’s Law for 10.02.15 Prepare for revision lesson

Starter Activity Complete True and False activity to demonstrate knowledge gained last week and to introduce forces. A scalar is a quantity which is describe by both magnitude and direction. Weight is the quantity of matter a body possesses. Inertia is the reluctance of the body to move or change its state of motion. Velocity is the rate of change in distance or body’s movement per unit of time Momentum is the amount of motion a body possesses and is the product of mass and velocity Force-time graph: net impulse is positive when an athlete is accelerating Force-time graph: a runner is at constant velocity when the net impulse is negative A shot putter performs turns to increase impulse by maximising the time over which a force is applied.

Starter Activity Complete True and False activity to demonstrate knowledge gained last week and to introduce forces. A scalar is a quantity which is describe by both magnitude and direction. F (vector) Weight is the quantity of matter a body possesses. F (mass) Inertia is the reluctance of the body to move or change its state of motion. T Velocity is the rate of change in distance or body’s movement per unit of time F (speed) Momentum is the amount of motion a body possesses and is the product of mass and velocity Force-time graph: net impulse is positive when an athlete is accelerating Force-time graph: a runner is at constant velocity when the net impulse is negative F A shot putter performs turns to increase impulse by maximising the time over which a force is applied.

Exam Q Heptathletes are required to complete the 200metre sprint. A 200metre runner must exert a large force in a short period of time to generate an impulse. Sketch and label a graph to show the impulse generated during the acceleration phase of a 200metre race. (3 marks)

Answer Heptathletes are required to complete the 200metre sprint. A 200metre runner must exert a large force in a short period of time to generate an impulse. Sketch and label a graph to show the impulse generated during the acceleration phase of a 200metre race. (3 marks)   A. X Axis – (time)/milliseconds/seconds B. Y Axis – (force)/Newton’s C. Shape of graph – negative and positive components of force shown with negative first D. Positive impulse clearly larger than negative impulse E. Positive and negative (force) labelled

Question Explain, in terms of a player moving towards the ball in tennis, the difference between velocity and acceleration. (3 marks)

Answer Explain, in terms of a player moving towards the ball in tennis, the difference between velocity and acceleration. (3 marks)   A. Velocity = rate of change of displacement/displacement ÷ time; (Not speed, not distance) B. How fast/quickly player moves towards ball; C. Acceleration (not speed) = rate of change of velocity/change in velocity ÷ time (taken to change)/[Vf - Vi] ÷ time/a = !v ÷ t; D. Push off ground to accelerate (not speed)/change velocity; E. (Both) have direction/are vectors. 3 marks

Factors affecting a force A force can be described as a ‘push or a pull’ When describing a force you must consider: Size or magnitude Direction of force The position of the force Activity – five main factors to consider, can you draw them onto the sprinter?

Forces acting on a sprinter

Forces acting on a sprinter

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

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

Newton’s First Law: Law of Inertia 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 Second Law: Law of acceleration 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 Third Law – the Law of action and reaction 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. 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

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.

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 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.