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# P4 lesson part one

## on Oct 21, 2011

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science gcse core, additional and triple powerpoints

science gcse core, additional and triple powerpoints

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## P4 lesson part onePresentation Transcript

• Explaining motion Route map Over the next 12 lessons you will study : Friday 21 October 2011 P4.1 Forces in all directions P4.2 How objects start to move P4.3 Friction P4.4 Reaction of surfaces End of module test P4.5 How fast P4.6 Modelling motion P4.7 Force, interaction and momentum P4.8 Change in momentum P4.9 Car safety P4.10 Laws of motion P4.11 Work and energy P4.12 Kinetic and gravitational potential energy
• P4.1 Forces in all directions Decide whether the following statements are true or false:
• Lesson objectives:
• The effects of forces on a moving or stationary object
• How forces arise when two objects interact
We will focus on. Friday 21 October 2011 First activity: Apart form pushing and pulling an object what other event can results when a force is applied to a moving or stationary object and give examples for each event that you list ? Literacy: Forces, push, pull squashing, changing direction, accelerating, decelerating, friction, gravity, electrostatic, magnetism, opposite, opposing, resultant and newtons PLTS Independent enquirers Creative thinkers Reflective learners Team workers Effective participators Self managers Numeracy: Forces are measured in Newtons (N). The value of g here on Earth is 9.81 N/kg which is normally rounded up to 10N/kg when doing calculations. We will focus on planning and carrying out research, appreciating the consequences of decisions
• P4.1 Extension questions: 1: List three examples of the consequences of a force acting in pairs on a object ? 2: Give one example of distant forces include gravity, magnetism and electrostatic forces ? 3: Give three examples where a pair of balanced forces act on an object and three examples of a unbalanced pair of forces acting on a object ? 4: What unit is forces measured in ? Know this: a: Know the effects of paired forces on a moving or stationary object. b: Know the difference between a contact force and a force that acts at a distance. Friday 21 October 2011 Introduction: Forces always arise from an interaction between two objects. Although you cannot see force you see the consequences of a force acting on a pair of objects. The two forces in an interaction pair are: equal in size and opposite in direction : Forces can push or pull an object (stationary or moving), change its direction or shape The size of a force is always measure in Newtons. In addition to contact forces, there are forces that act at a distance. The forces caused by gravity, magnetism and electrostatic charges are good examples of distant forces. Forces in all directions
• P4.1 a Look at the photograph and information and answer all the questions: When forces are balanced an object in motion will tend to stay in motion, and an object at rest will tend to stay at rest. When you are sitting on a chair, gravity exerts a force pulling your mass down, with the chair exerting an equal and opposite force on your body. Unless there is an external force acting on you, the chair and you will stay at rest. Look at the picture of the female sitting in the chair...why are the arrows on the picture the same size ? Look at the picture of the F1 racing car, work out the resultant force from engine thrust and air drag and internal resistance ? If a weight lifter lifts a weight with a mass of 100 kg and hold the weight steady above his head…what force must his arms be exerting of that weight in newtons ? Up thrust 4000N Gravity 4000N Air drag and internal resistance 70,000N Engine thrust 70,000N Moving at constant speed Up thrust Gravity 550N 550N Muscle Gravity 100N 100N Key concepts
• P4.1 b Look at the photograph and information and answer all the questions: The value of g (gravitational pull) on Earth is 9.81 Nkg -1 . This is normally rounded up to 10 Nkg -1 for convenience during calculations. Therefore, an object with a mass of 60 kg would have a weight of 600 N, since gravity exerts a force of 10 Newtons on every kilogram. If you move from the Earth’s surface to space, gravitational force becomes less until you are completely weightless, far out in space. Explain why the forces of attraction between Earth and a car is larger than the forces of attraction between Earth and an apple ? Work out the weight here on Earth of the following objects a) Human with a mass of 45 Kg b) Car with a mass of 1850 Kg and c) Apple with a mass of 0.1 Kg A pupil thinks that gravity pulls objects downwards...explain why his explanation of gravity is not completely right ? 10NKg -1 10NKg -1 10NKg -1 10NKg -1 Key concepts
• P4.1 c Look at the photograph and information and answer all the questions: Forces applied through simple devices like a spanner allows us to many jobs that would be impossible without these tools. Most simple tools use the principle of levers or moments. Using a lever allows us to apply a small force over a large distance through a pivot point to move a larger load force. The longer the lever the easier the job, because longer levers give a bigger turning effect ! Give five examples where work is being done, for example a baker kneading (squashing and squeezing) bread dough ? A lever make things easier by amplifying a force...which of the following use this effect a) a screwdriver b) wheel brace c) scissors d) knife e) drawing pin ? You wanted to break into a locked garage that has a very large padlock ...would you bring a short or a long crow bar to force the padlock open ? Key concepts
• P4.1 Plenary Lesson summary: slow newtons direction pairs Friday 21 October 2011 Examples of contact and distant forces are al around us. An object at rest on a table, a car accelerating away form a set of traffic lights, a falling apple, a fridge magnet. Useful work is done be apply a force in a certain direction. Examples of useful work done include push and pull forces, change direction and shape of an object How Science Works: Research into how forces begin to move objects. Look at how rocket, jet and car engines apply a force to move rockets, planes and cars. Preparing for the next lesson: Forces are measured in ________ and act in ____ that are equal in size and opposite in _________. Although you cannot see a force you can see the result of a force, where an object will speed up, ______ down, change direction or shape. Decide whether the following statements are true or false : False True 3: A stationary object has equal forces acting on it in opposite directions ? False True 2: Both gravity and magnetism are forces that act at a distance ? False True 1: Forces are measured in kilo joules or joules ?
• P4.2 How objects start to move Decide whether the following statements are true or false:
• Lesson objectives:
• Understand how an unbalanced force acting on an object can cause that object to move
• Understand how a force is applied by a rocket, jet and car engine
Friday 21 October 2011 First activity: Forces are measure in Newtons. The force exerted by the Earth’s gravitational field strength on mass is 9.81 N Kg -1 . What is the weight in Newtons for an object with a mass or a) 1 Kg b) 10 Kg c) 60 Kg and d) 500 Kg ? PLTS Independent enquirers Creative thinkers Reflective learners Team workers Effective participators Self managers Literacy: Forces, push, pull, squashing, changing direction, accelerating, decelerating, opposite, opposing, resultant force, friction, newtons, thrust, jet engine rocket and car engine Numeracy: The average family car engine exerts about 400 N Kg -1 of torque through the front wheels. A rock engine can exert up to 30,000,000 N Kg -1 of thrust to overcomes Earth’s gravitational field. We will focus on trying out alternatives or new solutions and follow ideas through
• Extension questions: 1: A rocket engine forces hot gases downwards and moves the rockets upwards toward space. Draw two rocks and show the forces acting on the rock before engine ignition and during lift off ? 2: If a boat is moving forwards, in what direction is the propeller forcing the water ? 3: Explain why faster cars require large engines ? 4: When you accelerates form stand still in a car the engine exerts a force through the wheels. What forces does this overcome to move the car ? Know this: a: Know that an unbalanced force acting on an object can change is speed. b: Know that engines (rocket, jet and car) apply forces in order to move an object. Friday 21 October 2011 Introduction: When objects begin to move or accelerate a contact force acting on an object is sufficiently large to overcome the opposing force and begin accelerating the object. In a rocket, the thrust of the engines overcomes the force of gravity acting in the opposite direction. A car engine supplies sufficient force to overcome the friction between the car tyres and the road and the internal resistance of the engine and other moving parts. P4.2 How objects start to move
• P4.2 a Look at the photograph and information and answer all the questions: Both the size and the direction of a force is important. We can show the direction of the force by using an arrow drawn in a particular direction. The size of the force acting in any given direction can be indicated using a scale – for example, one centimetre for one Newton or by writing on the arrow the size of the force in Newtons. Forces are always in pairs, so the resultant or overall force must be calculated. The engine thrust from a lorry is 16,000N. The air drag and internal resistance is 4,500N…work out the resultant force acting on the lorry and what happens to its speed ? Up thrust 4000 N Gravi ty 4000N Air drag and internal resistance 2,000 N Engine thrust 60,000 N Constant acceleration Look at the picture of the roller coaster...why are the arrows on the picture not the same size and work out the resultant force acting downwards on the people ? Look at the picture of the F1 racing car, work out the resultant force from engine thrust and air drag and internal resistance ? Up thrust 10,000 N Gravity 10,000 N Air drag and internal resistance 4,500 N Engine thrust 16,000N Key concepts
• P4.2 b Look at the photograph and information and answer all the questions: Rockets took first probes and finally humans into space. Escaping Earth’s gravity is not easy, requiring huge thrust and an escape speed of 40,000 km hr -1 . Millions of litres of fuel is used during take off. The Saturn rockets that launched the Apollo missions to the moon were single use multi stage rockets. Recently they have been replaced by multi use rockets like those used to launch the space shuttle. Explain the difference between a one use multi-stage rock and a multi-use rocket ? Who was the first human to orbit space back in 1961 ? NASA plan to send humans to Mars by 2050...explain why this will be a much harder task when compared to Neil Armstrong's lunar landing in 1969 ? Saturn Space shuttle Deep impact Mars Rocks and space exploration Key concepts
• 4.2 Plenary Lesson summary: speed forces car quicker Friday 21 October 2011 We rely on engines (rocket, jet car, lorry and motorbike) to provide a force. This force does useful work like moving a car form A to B. In engines, chemical energy contain in the fuel that it uses is converted into kinetic or moving energy. How Science Works: Research into friction and what is friction between two moving surfaces. Think about useful friction and examples where friction is unwanted. Preparing for the next lesson: An unbalanced contact pair of ______ acting on a object like a ____, lorry, plane or rocket will result in that object changing _______ or accelerating. Sports have a lower mass and larger engine to provide _________ acceleration when compared to normal family cars. Decide whether the following statements are true or false : False True 3: A jet engine works by hot gases pushing out of the rear of the plane ? False True 2: The friction between a car type and the road decreases when the road is wet ? False True 1: A boat propeller pulls water at the rear to make a boat go forwards ?
• P4.3 Friction Decide whether the following statements are true or false:
• Lesson objectives:
• Understand what friction is and that friction changes kinetic energy between two moving objects into heat energy
• Understand that in everyday life there is useful friction and unwanted friction
We will focus on. Friday 21 October 2011 First activity: Think of three examples where friction is useful, for example the friction between a shoe sole and the floor prevent you form slipping and three examples where friction is unwanted, for example the friction between moving parts in a car engine ? Literacy: Friction, surface, rough, smooth, moving, rubbing, lubricate, lubrication, oil, kinetic energy and heat . Numeracy: Only 17% of the chemical energy contained in petrol is converted into useful kinetic energy during a car journey. The remaining energy is spent overcoming the internal friction between the car’s moving parts. PLTS Independent enquirers Creative thinkers Reflective learners Team workers Effective participators Self managers We will focus on plan and carry out research, appreciating the consequences of decisions
• Extension questions: 1: Rub you hand together what do you notice and how would you reduce this friction effect ? 2: List three everyday examples where friction is a) useful and b) unwanted ? 3: How could we reduce friction between two moving objects ? 4: Explain why is it easier to drag a suitcase across a floor rather than carry it. Describe the different forces that you are overcoming ? 5: Explain why we oil a bicycle chain on a regular basis ? Know this: a: Know what friction is and that kinetic energy is converted into heat energy. b: Know that friction is useful and sometimes unwanted. Friday 21 October 2011
• Introduction:
• Ordinary friction between objects can be thought of as arising from surface roughness. Although two objects can appear to have relatively smooth surfaces, under the microscope, their surfaces can be extremely rough or pitted. This unevenness causes friction between moving objects, for example an engine piston moving inside a cylinder. Friction causes heat to build up as an object’s atoms or molecules gain kinetic energy.
• The amount of friction depends on:
• The materials from which the two surfaces are made.
• The roughness of the surface
• The speed of the two moving surfaces
P4.3 Friction
• Key concepts P4.3 a Look at the photograph and information and answer all the questions: Although two objects can appear to have smooth surfaces, under the microscope, their surfaces can be extremely rough or pitted. This unevenness causes friction between moving objects, for example an engine piston moving inside an engine cylinder. Friction causes heat to build up as an object’s atoms gain kinetic energy. Friction is sometimes useful, sometimes unwanted. Look at the picture opposite left...explain why friction between the ice and the ice axe is very useful ? If you were to look at the underside of the frog’s foot pads using a microscope, what would it’s appearance be like...describe ? Give two ways you could reduce friction between two moving surfaces ?
• P4.3 b Look at the photograph and information and answer all the questions: The household match relies on the force of friction to work. Ordinary friction between objects can be thought of as arising from surface roughness. Under the microscope, a match surface can be extremely rough or pitted. When you strike the match the surface atoms begin to heat up and ignite the sulphur compound. Explain why they use sand paper on the side of the box when striking the match ? Explain how friction is being used to start a fire by using two wooden sticks ? When drilling through thick sheet metal, explain why they use a lubricant such as water or oil ? Key concepts
• P4.3 Plenary Lesson summary: heat rough energy eye Friday 21 October 2011 Without friction, we would even be able to stand up. Friction is useful in many examples but it is also unwanted and moving objects like cars, lorries and buses spend large amounts of energy overcoming internal friction. Moving through gases (air) and fluids (water) also causes friction. How Science Works: Research into objects that are at rest and subjected to balanced forces and object that are subjected to a unbalanced or resultant force. Preparing for the next lesson: Because all surfaces are ________, even those that look smooth to the naked ____, friction is a consequence of surface that move against one another. When rough surface move or slide against one another kinetic _______ is turned into _____ energy. Decide whether the following statements are true or false : False True 3: Water on the roads reduces friction between a car’s tyre and the road ? False True 2: Lubricates like oil and water increase friction between two moving surfaces ? False True 1: Rub your hand together and they become warm because of friction ?
• P4.4 Balanced and unbalanced forces Decide whether the following statements are true or false:
• Lesson objectives:
• Understand when forces are in balance acting on an object at rest
• Understand that when forces are unbalanced and acting on an object a change in speed, direction or shape can result
Friday 21 October 2011 First activity: Think of a stationary object like a book on a table top. It is not moving but it is subject to a pair of contact forces acting on it. If the book has a mass of 1 Kg work out the forces pulling it downwards and the size of the opposite force. Show this in a small diagram ? PLTS Independent enquirers Creative thinkers Reflective learners Team workers Effective participators Self managers Literacy: Forces, push, pull squashing, changing direction, accelerating, decelerating, friction, gravity, electrostatic, magnetism, opposite, opposing, resultant and newtons Numeracy: Forces are measured in Newtons (N). The value of g here on Earth is 9.81 N/kg which is normally rounded up to 10N/kg when doing calculations. We will focus on review progress, acting on the outcomes.
• Extension questions: 1: Give three examples where everyday objects are subjected to balanced forces ? 2: Gravity exerts a force of 600 N on a body with a mass of 60 kg. What’s the force acting in the opposite direction if the body is stationary ? 3: Give three examples where everyday objects are subjected to unbalanced forces? 4 An object is subjected to a force of 10N to the right and 5N to the left....work out the resultant force acting on that object ? Know this: a: Know that when an object it at rest balanced forces act upon it opposite in direction. b: An object that is changing its speed, direction or shape is being subjected to an unbalanced force. Friday 21 October 2011 Introduction: “An object in motion will tend to stay in motion, and an object at rest will tend to stay at rest unless the object is acted upon by an outside force.” Example: When you are sitting on a chair, gravity exerts a force pulling your mass down, with the chair exerting an equal and opposite force on your body. Unless there is an external force acting on you, the chair and you will stay at rest Remember if an object changes its speed, direction or shape, then a resultant force must be acting on it, for example if you kick a football or fire a gun these are both examples where an object change its speed P4.4 Balanced and unbalanced forces
• Key concepts P4.4 a Look at the photograph and information and answer all the questions: In the first example, gravity pulls downward on the jet with a force of 30,000 N. The thrust of the jet engines is pushing upwards on the jet with the same force of 30,000 N. In the second example, gravity pulls downward on the boat with a force of 60,000N. The up thrust from the water is pushing upwards on the boat with the same force of 60,000N. In the third example, gravity pulls downward on the building with a force of 3,000,000N. The ground or building foundations are pushing upwards with the same force of 3,000,000N. Give three examples where a pair of balanced forces are acting on an object ? A car is moving at a constant speed of 30 ms -1 . explain the forces acting on the car and are they balanced ? Up thrust Gravity 30,000 N 30,000 N Buoyancy Gravity 60,000 N 60,000 N Up thrust Gravity 3,000,000 N 3,000,000 N Forces in balance
• P4.4 b Look at the photograph and information and answer all the questions: In the first example, two forces exists; the force applied to the ball by the leg or foot of the football player and the friction between the ground and the ball. The largest force is the force applied to the ball by the foot of the boy. In the second example, two forces exists; the force of the explosion form ignited the gun powder and the air resistance between the bullet and the atmosphere. The largest force is produced by the exploding gunpowder which propels forward the bullet in a straight line at very high speeds Explain why the gun recoils when it fires a bullet in the opposite direction ? As the footballer makes contact with the ball, the ball then moves. Explain the transfer of forces between the footballer’s leg and the ball ? Friction 20N Work 200N Friction 20N Work 200N Unbalanced forces Key concepts
• P4.4 Plenary Lesson summary: speed shape speeding rest Friday 21 October 2011 A force (push pull turning changing shape) is measured in Newtons. Gravity for example exerts a force of 10 newtons for every kilogram of mass here on Earth. Remember you cannot see a force but you can observe the consequence of a force acting on an object How Science Works: Research into how we calculate the speed of a moving object. Preparing for the next lesson: Unbalanced pairs of forces acting on an object results in that objects _________ up. Slowing down changing _______ or direction. A balanced pair of objects acting on an object will result in a object remaining at _____ or if moving at constant ______. Decide whether the following statements are true or false : False True 3: An object moving at a steady speed is subject to no forces acting on it ? False True 2: An accelerating object is subject to an unbalanced pair of forces acting on it ? False True 1: When you sit on a chair and remain still, a balanced pair of forces act on you ?
• P4.5 How fast are you going Decide whether the following statements are true or false:
• Lesson objectives:
• Understand that speed describes distance travelled over a certain time
• Understand how to calculate speed
We will focus on. Friday 21 October 2011 First activity: A bus travels 5 miles in 15 minutes a) work out is average speed and b) work out how long it too to travel i) 1 miles and II) 3 miles ? Literacy: Speed, distance travelled, time taken, speeding up, slowing down, accelerating, decelerating, speed gun, kilometres, miles, seconds and hours. Numeracy: In order to calculate speed you need to know the distance travelled in metres and the time taken for that distance to be travelled in seconds. The unit of speed is metres per second or ms -1 PLTS Independent enquirers Creative thinkers Reflective learners Team workers Effective participators Self managers We will focus on knowing setting goals and success criteria.
• Extension questions: 1: Calculate the speed in metres per second of a car if a) it moves 10 metres in 2 seconds b) 5 metres in 10 seconds and c) 15 metres in 3 seconds 2: If a car travels at 10 metres per second or 10ms -1 . How many metres would the car travel in a) ½ a second b) 1 second and c) 10 seconds 3: If a runner is travelling at 5 ms -1 . What time would it take him to cover a) 100 metres b) 200 metres and c) 1 km ? Know this: a: Know that speed describes the distance covered by the time taken. b: Know how to calculate speed of an moving object. Friday 21 October 2011 P4.5 How fast are you going Introduction: We can’t measure speed directly, we must therefore calculate the speed of a moving object : The speed of a moving object describes the distance travelled in metres over time in seconds. Knowing the speed of an object, allows you to calculate how long it will take the moving object to cover a certain distance. Calculating the speed in metres per second (ms -1 ) of an object is simple using the following formula: Speed = Distance travelled (m) Time taken (s) Units for speed = ms -1
• P4.5 a Look at the photograph and information and answer all the questions: Speed describes the distance travelled in metres over time in seconds. Knowing the speed of an object, allows you to calculate how long it will take the moving object to cover a certain distance. Calculating the speed in metres per second (ms -1 ) of an object is simple using the following formula: Speed (ms -1 ) = distance (m) / time (s) Explain why maximum speed limits are only 20 m.p.h on roads near schools and other public buildings ? Using the formula to work out speed solve the following; A cyclist travels 140 metres in 20 seconds...what is his average speed ? When motorways become wt, they often reduce the top speed from 70 m.p.h to 50 m.p.h. Explain why they do this ? Key concepts
• P4.5 b Look at the photograph and information and answer all the questions: Speed is how long it takes to travel a certain distance. In a hundred metres race Usain Bolt travelled exactly 100 metres in just 9.68 seconds. This time was the fastest recorded time every. We can work out is average speed by dividing the distance cover (100 m) by the time taken (9.68 S). This works out to be 10.33 metres per second or 10.33 mS -1 . If a person walked for 10 minutes at an average speed of 3 mS -1 ...work out how many metres that person covered ? If Usain Bolt increased his average speed to 10.5 mS -1 ...what would be his time for the 100 m sprint ? Usain Bolt shattered the 100 m sprint record winning by a huge margin…the second place runner took 9.84 second to complete the race...work out his average speed ? Key concepts
• P4.5 Plenary Lesson summary: moving directly calculate time Friday 21 October 2011 The highest road speed every recorded on British roads was 146 mph done by a 1000 cc super bike. The national speed limit for all cars in the UK is 90 m.p.h (for me) and 70 m.p.h for the rest of the car drivers on the road. How Science Works: Research into how we can use distance time graphs to describe the motion of a moving object. Preparing for the next lesson: We have to _______ the speed of a ___________ object using distance covered in metres and _______ taken in seconds. We cannot measure the speed of a moving object ___________. Decide whether the following statements are true or false : False True 3: Velocity can also tell us the direction that an object is moving ? False True 2: Speed cameras work by calculating distant travelled over time taken ? False True 1: Speed can also be measure in miles per hour in addition to metres per second ?
• P4.6 Modelling motion Decide whether the following statements are true or false:
• Lesson objectives:
• Understand how distant time graph can be used to describe, summarise or analyse an objects motion
• Understand what constant speed, changing speed or at rest looks like on a distant time graph
Friday 21 October 2011 First activity: Think of a simple graph with a Y and X axis. What would a graph look like describing constant speed of a) 30 m.p.h and b) 70 m.p.h ? PLTS Independent enquirers Creative thinkers Reflective learners Team workers Effective participators Self managers Literacy: Speed, distance travelled, time taken, speeding up, slowing down, accelerating, decelerating, speed gun, kilometres, miles, seconds and hours. Numeracy: Distant time graphs can describe a journey and the speed of an object. Graphs are used to convey visual information rather than using hundreds of numbers. We will focus on analysing and evaluating information judging its relevance and value.
• Extension questions: 1: A car travels 12 metres in one second. Calculate its speed in ms -1 and b) its speed in kh -1 (there are 3,600 second in one hour) ? 2: Calculate the speeds of the following vehicles a) a cycle travelling 8 miles in 30 minutes b) a car on a motorway travelling at 6.5 miles in six minutes and c) a jet aircraft travelling 300 miles in 20 minutes ? 3: Where there is a speed camera there are always marking on the road at one metre apart. Explain why these markings are necessary 4: Why are speed limits for cars and lorries lower in built up areas ? Know this: a: Know how both distant time graph and speed time graphs describe a journey of a moving object. Friday 21 October 2011
• Introduction:
• We can use a distance time graph and speed time graphs to describe a journey rather than using words and numbers.
• A distant time graph shows how far a ,moving object is from the starting point at every instant.
• A speed time graph shows the speed of a moving object a every instant.
• These distant and speed time graph not only help us picture the journey, how far an object has travelled and how fast it is moving but also it helps us analyse a journey over time.
P4.6 Modelling motion
• P4.6 a Look at the photograph and information and answer all the questions: Using distance time graphs, you can see that the steeper the slope, the greater the object’s speed. We can use the gradient of the slope to calculate the speed of the moving object: Using the graph, the speed at point C is worked out by dividing the distance travelled (250 m. change in y) by the time taken (250 s. change in x) This gives a speed or gradient of 1 ms -1
• Look at the distance time graph above left and calculate the following:
• Work out speed or gradient of the moving object at points A and B.
• Work out the total distance travelled.
• How long in seconds did the journey take.
• Look at the speed time graph below left and calculate the following:
• What was the speed at A and C
• For how many seconds did the object travel at 0 ms -1 at point B
Key concepts 0 50 100 150 200 250 300 350 400 Distance travelled (m) Time (s) 0 100 200 300 400 500 600 A B C D 250s 250m 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Speed (ms -1 ) Time (s) 0 100 200 300 400 500 600 A B C D
• P4.6 b Look at the photograph and information and answer all the questions: The distance time graph shows a journey: The bus left the depot and took 200S to travel 150m to a set of traffic lights. The bus waited here for 200S while the lights changed to green. The bus then took a further 50S to travel 100m. It then took 200S to travel 50m and then a further 50S to travel a further 100m. It then stopped back at the bus station. At which point A, B, C, D or E was the bus a) not moving b) moving with the fastest average speed ? Using your answer from question 1, if you can walk an average of 3 ms -1 ...would it be quicker to walk or take the bus to cover the 400 metre journey ? The total time for the journey was 700 seconds with the total distance covered by the bus was 400 metres...work out its average speed ? Key concepts time (s) time (s) distance (m) distance (m) time (s) distance (m) time (s) distance (m) A B C D
• P4.6 c Look at the photograph and information and answer all the questions: A tachograph is a device that combines the functions of a clock and a speedometer. Fitted to a motor vehicle, a tachograph records the vehicle's speed and whether it is moving or stationary. The mechanical tachograph writes on a round piece of paper which constantly turns throughout the work day. The marker moves further from the center the faster the vehicle is moving. An entire rotation encompasses 24 hours. Why are the drivers of lorries and HGV good vehicles only allowed to drive for hours in any 24 hr period ?
• Look at the close up of the tachograph below left.
• Describe the lorries journey between 10 and 11 ?
• What was the top speed reached during the journey ?
• How long was the lorry stationary for ?
The tachograph Key concepts
• P4.6 Plenary Lesson summary: moving moves measured time Friday 21 October 2011 Many athletes will now do a speed-time graph to analyse their running performance over the duration of their race. Using a speed time graph they will lean where the fastest and also lowest part of their race is and train to improve their performances. How Science Works: Research into forces, momentum and changes in momentum. Preparing for the next lesson: Speed can not be __________ directly it can only be calculate. Distance and speed ______ graphs can show information on the distance and speed of a _______ object like a car or a bus. These graphs are easier to visual how an object ____ over time Decide whether the following statements are true or false : False True 3: A speed time graph can show when an object is slowing down or speeding up ? False True 2: A distant time graph can summarise a moving object journey over time ? False True 1: The units of speed are ms -1 ?